Unburnt fuel in exhaust system/engine bearings worn out(low oil pressure)

What is your question?

Okay, so I had a hard time in -40°f for the last 5 days, couldn't start my vehicle at all through those 5 days. And it raised to -20°f this morning, gave it a try, charged battery, engine block heater plugged in for hours and finally starts hallelujah, until the engine light flashing doesn't stop, low engine power while shifting reverse and drive. Idk what to think about it, I looked up everywhere, and the most I keep seeing is that it flooded or misfired too many times that there's fuel in the exhaust system, idk how to resolve the issue, could be oil pressure too because when I rev it up past 2000rpm it stops flashing, but doesn't go away. I'm lost and need help, might have a friend come by with a code reader but I'm not too sure he has one I can use. Please help lmao

How long has your 2003 GMC Sierra 1500 HD had this problem?

Just started today 1/29/24