Why is my phone really dead?

2 mos ago, i got this problem with my Nexus. it always on the screen where there is an X at the center. i was glad that i was able to find a solution to that by pressing the volume up and power button at the same time that lead me to the bootloader screen. it was effective but i was devastated when i open my phone i lost all my apps. so i decided to reboot it again thinking i might retrieve my application at the bootloader menu. when i was about to reboot, i accidentally slip off the battery that turns it off without rebooting. now, i was very disappointed when i place the battery back., my phone does not turn on, nor even shows the battery meter when im charging it, it only heats up. can you please help me with this? it is so depressing because i love that phone coz i have lots of important files in there. hope you can help with this....please.