iMac keeps randomly restarting after using bootable drive

So I have a late 2012 27 inch iMac. The Fusion Drive started showed SMART failure status. So I used Disk Warrior - it couldn't fix it and that confirmed my 120 GB Internal SSD SMART was failing but the 1TB Internal HDD was fine (I was told by someone usually the HDD fails). So I bought a 256GB WD SSD with an enclosure from Amazon and created a bootable drive to install Mac OS on it (clean install rather than clone, etc - I had my data saved on another external drive). I also split up the internal Fusion Drive into the separate Internal SSD and Internal HDD and formatted both so after bootable, I could use them (I don't use the SSD due to failure status but use the HDD - I have noted sometimes slow downs when using the HDD, maybe its starting up from sleep mode or it has just gotten old, or it has errors/is failing but isn't showing. But I only save data on it that I don't mind losing - interim / working data which has backups). All in all - generally, the computer now seems to be working fine, in fact somewhat better than previously as often the OS would briefly hang while working on it. (I also upgraded RAM a few months ago to be 8GB x 4 - with 2 bought from Amazon - I had done various tests to check RAM was working fine and the internal hardware test passed the RAMs).

So anyway - I have had this new setup for a month or so. But every so often, I keep getting the computer restarting randomly - not sure if it is an app or the drive or what. That's where I need your help. I have pasted the error that pops up when the computer has restarted below. Any help / suggestions / fixes would really help:

• Panic Report ***

panic(cpu 4 caller 0xffffff8008d8776f): Kernel trap at 0xffffff800925eef4, type 13=general protection, registers:

CR0: 0x000000008001003b, CR2: 0x0000000105ab5000, CR3: 0x000000000cf25000, CR4: 0x00000000001626e0

RAX: 0x304d54040a0f0492, RBX: 0x2156314c54040a0f, RCX: 0x0000000000000001, RDX: 0x0000000000000000

RSP: 0xffffffa3b6ccbc40, RBP: 0xffffffa3b6ccbca0, RSI: 0x0000000000000001, RDI: 0x0000000000100000

R8: 0xffffff800961bdd8, R9: 0x0000000000000001, R10: 0xf800000000000000, R11: 0x0000000000000001

R12: 0x0000000000000040, R13: 0x0000000000000005, R14: 0x000000000000014c, R15: 0xffffffffffffffff

RFL: 0x0000000000010206, RIP: 0xffffff800925eef4, CS: 0x0000000000000008, SS: 0x0000000000000000

Fault CR2: 0x0000000105ab5000, Error code: 0x0000000000000000, Fault CPU: 0x4, PL: 0, VF: 0

Backtrace (CPU 4), Frame : Return Address

0xffffff8008b4e290 : 0xffffff8008c6c1c6

0xffffff8008b4e2e0 : 0xffffff8008d95274

0xffffff8008b4e320 : 0xffffff8008d87544

0xffffff8008b4e390 : 0xffffff8008c1e1e0

0xffffff8008b4e3b0 : 0xffffff8008c6bc3c

0xffffff8008b4e4e0 : 0xffffff8008c6b9fc

0xffffff8008b4e540 : 0xffffff8008d8776f

0xffffff8008b4e6b0 : 0xffffff8008c1e1e0

0xffffff8008b4e6d0 : 0xffffff800925eef4

0xffffffa3b6ccbca0 : 0xffffff800929ffdb

0xffffffa3b6ccbd40 : 0xffffff80092a0af7

0xffffffa3b6ccbd80 : 0xffffff7f8a246de2

0xffffffa3b6ccbdb0 : 0xffffff7f8a24291b

0xffffffa3b6ccbdf0 : 0xffffff7f8a2423be

0xffffffa3b6ccbe40 : 0xffffff80092731fd

0xffffffa3b6ccbe80 : 0xffffff8009272f41

0xffffffa3b6ccbf00 : 0xffffff8009272467

0xffffffa3b6ccbf50 : 0xffffff80092740c6

0xffffffa3b6ccbfa0 : 0xffffff8008c1d557

Kernel Extensions in backtrace:

com.apple.iokit.IOUSBMassStorageDriver(140.70.2)[91925DA5-1D2A-3444-A53B-1432B6363BA7]@0xffffff7f8a233000->0xffffff7f8a260fff

dependency: com.apple.iokit.IOUSBHostFamily(1.2)[CE61D704-9BFF-308E-BC1C-56FF071DBB74]@0xffffff7f89847000

dependency: com.apple.iokit.IOStorageFamily(2.1)[F27A8A2A-6662-3608-83BD-415037509E01]@0xffffff7f89451000

dependency: com.apple.iokit.IOSCSIArchitectureModelFamily(404.30.2)[4734E6C9-B881-32C8-BE1F-4D9848A52895]@0xffffff7f894f1000

BSD process name corresponding to current thread: kernel_task

Mac OS version:

17G65

Kernel version:

Darwin Kernel Version 17.7.0: Thu Jun 21 22:53:14 PDT 2018; root:xnu-4570.71.2~1/RELEASE_X86_64

Kernel UUID: 1AE5ACFD-3B6F-3D74-AD52-31F1430DBC6F

Kernel slide: 0x0000000008a00000

Kernel text base: 0xffffff8008c00000

__HIB text base: 0xffffff8008b00000

System model name: iMac13,2 (Mac-FC02E91DDD3FA6A4)

System uptime in nanoseconds: 19094354786369

last loaded kext at 257677708229: com.apple.filesystems.msdosfs 1.10 (addr 0xffffff7f8c5d2000, size 69632)

last unloaded kext at 1056962323936: com.apple.driver.AppleUSBMergeNub 900.4.1 (addr 0xffffff7f8a520000, size 12288)

loaded kexts:

com.apple.filesystems.smbfs 3.2.3

com.apple.driver.AppleBluetoothMultitouch 92

com.apple.driver.AudioAUUC 1.70

com.apple.driver.AppleHWSensor 1.9.5d0

com.apple.driver.AGPM 110.23.37

com.apple.driver.ApplePlatformEnabler 2.7.0d0

com.apple.driver.X86PlatformShim 1.0.0

com.apple.filesystems.autofs 3.0

com.apple.driver.AppleMikeyHIDDriver 131

com.apple.driver.AppleMikeyDriver 281.52

com.apple.driver.AppleHDA 281.52

com.apple.AGDCPluginDisplayMetrics 3.20.13

com.apple.driver.AppleUpstreamUserClient 3.6.5

com.apple.driver.pmtelemetry 1

com.apple.iokit.IOUserEthernet 1.0.1

com.apple.GeForce 10.3.2

com.apple.iokit.IOBluetoothSerialManager 6.0.7f10

com.apple.Dont_Steal_Mac_OS_X 7.0.0

com.apple.driver.AppleIntelHD4000Graphics 10.3.6

com.apple.driver.eficheck 1

com.apple.driver.AppleBacklight 170.12.6

com.apple.driver.AppleHV 1

com.apple.driver.AppleThunderboltIP 3.1.1

com.apple.driver.AppleLPC 3.1

com.apple.driver.AppleSMCLMU 211

com.apple.driver.AppleOSXWatchdog 1

com.apple.driver.AppleIntelSlowAdaptiveClocking 4.0.0

com.apple.driver.AppleIntelFramebufferCapri 10.3.6

com.apple.driver.AppleMCCSControl 1.5.5

com.apple.iokit.SCSITaskUserClient 404.30.2

com.apple.driver.AppleUSBStorageCoexistentDriver 439.70.3

com.apple.AppleFSCompression.AppleFSCompressionTypeDataless 1.0.0d1

com.apple.AppleFSCompression.AppleFSCompressionTypeZlib 1.0.0

com.apple.AppleSystemPolicy 1.0

com.apple.BootCache 40

com.apple.filesystems.hfs.kext 407.50.6

com.apple.driver.AppleSDXC 1.7.6

com.apple.driver.AirPort.Brcm4360 1240.19.1a3

com.apple.iokit.AppleBCM5701Ethernet 10.3.1

com.apple.driver.AppleAHCIPort 329.50.2

com.apple.driver.AppleACPIButtons 6.1

com.apple.driver.AppleRTC 2.0

com.apple.driver.AppleHPET 1.8

com.apple.driver.AppleSMBIOS 2.1

com.apple.driver.AppleACPIEC 6.1

com.apple.driver.AppleAPIC 1.7

com.apple.driver.AppleIntelCPUPowerManagementClient 220.50.1

com.apple.nke.applicationfirewall 183

com.apple.security.quarantine 3

com.apple.security.TMSafetyNet 8

com.apple.driver.AppleIntelCPUPowerManagement 220.50.1

com.apple.driver.AppleBluetoothHIDKeyboard 205

com.apple.driver.AppleHIDKeyboard 205

com.apple.driver.IOBluetoothHIDDriver 6.0.7f10

com.apple.driver.AppleMultitouchDriver 1404.4

com.apple.driver.AppleInputDeviceSupport 1404.3

com.apple.kext.triggers 1.0

com.apple.driver.DspFuncLib 281.52

com.apple.kext.OSvKernDSPLib 526

com.apple.nvidia.driver.NVDAGK100Hal 10.3.2

com.apple.nvidia.driver.NVDAResman 10.3.2

com.apple.iokit.IOSerialFamily 11

com.apple.iokit.IOAVBFamily 680.2

com.apple.plugin.IOgPTPPlugin 680.15

com.apple.driver.AppleBacklightExpert 1.1.0

com.apple.driver.AppleSSE 1.0

com.apple.iokit.IONDRVSupport 519.20

com.apple.driver.AppleHDAController 281.52

com.apple.iokit.IOHDAFamily 281.52

com.apple.iokit.IOAudioFamily 206.5

com.apple.vecLib.kext 1.2.0

com.apple.driver.AppleSMBusPCI 1.0.14d1

com.apple.driver.X86PlatformPlugin 1.0.0

com.apple.driver.IOPlatformPluginFamily 6.0.0d8

com.apple.AppleGPUWrangler 3.20.13

com.apple.iokit.IOSlowAdaptiveClockingFamily 1.0.0

com.apple.driver.AppleThunderboltEDMSink 4.1.4

com.apple.iokit.IOAcceleratorFamily2 378.26

com.apple.iokit.IOSurface 211.15

com.apple.AppleGraphicsDeviceControl 3.20.13

com.apple.driver.AppleSMBusController 1.0.18d1

com.apple.iokit.IOGraphicsFamily 519.20

com.apple.iokit.BroadcomBluetoothHostControllerUSBTransport 6.0.7f10

com.apple.iokit.IOBluetoothHostControllerUSBTransport 6.0.7f10

com.apple.iokit.IOBluetoothHostControllerTransport 6.0.7f10

com.apple.iokit.IOBluetoothFamily 6.0.7f10

com.apple.iokit.IOUSBMassStorageClass 4.0.4

com.apple.driver.usb.networking 5.0.0

com.apple.driver.usb.AppleUSBHostCompositeDevice 1.2

com.apple.driver.usb.AppleUSBHub 1.2

com.apple.filesystems.hfs.encodings.kext 1

com.apple.driver.AppleThunderboltDPInAdapter 5.5.5

com.apple.driver.AppleThunderboltDPOutAdapter 5.5.5

com.apple.driver.AppleThunderboltDPAdapterFamily 5.5.5

com.apple.driver.AppleThunderboltPCIDownAdapter 2.1.3

com.apple.iokit.IOAHCIBlockStorage 301.40.2

com.apple.driver.AppleThunderboltNHI 4.7.2

com.apple.iokit.IOThunderboltFamily 6.7.8

com.apple.iokit.IO80211Family 1200.12.2

com.apple.driver.corecapture 1.0.4

com.apple.iokit.IOEthernetAVBController 1.1.0

com.apple.driver.mDNSOffloadUserClient 1.0.1b8

com.apple.iokit.IOAHCIFamily 288

com.apple.driver.usb.AppleUSBEHCIPCI 1.2

com.apple.driver.usb.AppleUSBEHCI 1.2

com.apple.driver.usb.AppleUSBXHCIPCI 1.2

com.apple.driver.usb.AppleUSBXHCI 1.2

com.apple.driver.usb.AppleUSBHostPacketFilter 1.0

com.apple.iokit.IOUSBFamily 900.4.1

com.apple.driver.AppleUSBHostMergeProperties 1.2

com.apple.driver.AppleEFINVRAM 2.1

com.apple.driver.AppleEFIRuntime 2.1

com.apple.iokit.IOSMBusFamily 1.1

com.apple.iokit.IOHIDFamily 2.0.0

com.apple.security.sandbox 300.0

com.apple.kext.AppleMatch 1.0.0d1

com.apple.driver.AppleFDEKeyStore 28.30

com.apple.driver.AppleEffaceableStorage 1.0

com.apple.driver.AppleKeyStore 2

com.apple.driver.AppleUSBTDM 439.70.3

com.apple.driver.AppleMobileFileIntegrity 1.0.5

com.apple.iokit.IOUSBMassStorageDriver 140.70.2

com.apple.iokit.IOSCSIBlockCommandsDevice 404.30.2

com.apple.iokit.IOSCSIArchitectureModelFamily 404.30.2

com.apple.driver.AppleCredentialManager 1.0

com.apple.driver.KernelRelayHost 1

com.apple.iokit.IOUSBHostFamily 1.2

com.apple.driver.usb.AppleUSBCommon 1.0

com.apple.driver.AppleBusPowerController 1.0

com.apple.driver.AppleSEPManager 1.0.1

com.apple.driver.IOSlaveProcessor 1

com.apple.driver.DiskImages 480.60.1

com.apple.iokit.IOStorageFamily 2.1

com.apple.iokit.IOReportFamily 31

com.apple.iokit.IOTimeSyncFamily 680.15

com.apple.iokit.IONetworkingFamily 3.4

com.apple.driver.AppleACPIPlatform 6.1

com.apple.driver.AppleSMC 3.1.9

com.apple.iokit.IOPCIFamily 2.9

com.apple.iokit.IOACPIFamily 1.4

com.apple.kec.Libm 1

com.apple.kec.pthread 1

com.apple.kec.corecrypto 1.0

EOF

Model: iMac13,2, BootROM IM131.0115.B00, 4 processors, Intel Core i7, 3.4 GHz, 32 GB, SMC 2.11f14

Graphics: NVIDIA GeForce GTX 680MX, NVIDIA GeForce GTX 680MX, PCIe

Memory Module: BANK 0/DIMM0, 8 GB, DDR3, 1600 MHz, 0x859B, 0x435438473353313630424D2E433136465044

Memory Module: BANK 1/DIMM0, 8 GB, DDR3, 1600 MHz, 0x80AD, 0x484D5434314753364D465238432D50422020

Memory Module: BANK 0/DIMM1, 8 GB, DDR3, 1600 MHz, 0x859B, 0x435438473353313630424D2E433136465044

Memory Module: BANK 1/DIMM1, 8 GB, DDR3, 1600 MHz, 0x80AD, 0x484D5434314753364D465238432D50422020

AirPort: spairport_wireless_card_type_airport_extreme (0x14E4, 0xF4), Broadcom BCM43xx 1.0 (7.21.190.18.1a3)

Bluetooth: Version 6.0.7f10, 3 services, 27 devices, 1 incoming serial ports

Network Service: Ethernet, Ethernet, en0

Serial ATA Device: APPLE HDD ST1000DM003, 1 TB

Serial ATA Device: APPLE SSD SM128E, 121.33 GB

USB Device: USB 2.0 Bus

USB Device: Hub

USB Device: FaceTime HD Camera (Built-in)

USB Device: USB 2.0 Bus

USB Device: Hub

USB Device: Hub

USB Device: BRCM20702 Hub

USB Device: Bluetooth USB Host Controller

USB Device: USB 3.0 Bus

USB Device: asm1153e

USB Device: My Book 1230

Thunderbolt Bus: iMac, Apple Inc., 23.4