Low oil pressure & stalled out engine on a 2012 F150 XLT Flex fuel

I need someone that can point me in the right direction on where to look & check first for this issue with my 2012 F150 Xlt....... Yesterday when I was on my lunch break I was going 70mph down the TX freeway. When all of a sudden my truck started to decelerate. I felt the difference & took my foot off the gas & let her ride an feel for a change or a change in the trucks instruments. Soon after that low oil pressure light kick on & I couldn't accelerate at all. I Pull over on the side my truck was rumbling. I turn off the engine hop out to check the dip stick. She was fill all the way to the top of the stick, smelled a little like fuel , & look watery. I know its fuel/oil dilution. The next morning she wont turn over fully {she whippering} & the oil pressure lights gone. PLEASE IF ANYONE KNOW ANYTHING AT ALL FOR THIS FIX PLEASE HELP. I do know the possible causes of this [Bad oil pressure switch, bad oil pump, head gasket broke, or fuel injector may need to be replaced or cleaned.] What I dont know is where to start or WHEREs THE BEST PLACE TO CHECK FIRST! PLEASE HELP ANYYHING WILL.