I'm in the room where everything explodes at the end, but when I head back down to the room, things start blowing up on the way. When I get into the final room, trigger the cutscene, and when I try to exit leaving the door I came from, I get INSANTLY fragged.
Am I doing something wrong?

Not sure what you're describing. I just ran out of the room and left, no issues. What is the 'final' room you're talking about?

your going to take damage you just got run to the right  and go up really fast and when you start going left u can get into a super run and do a short jump to fast run up the elevator shaft. I did this with 200 health, so it shouldn't be a problem

Thats really odd, I died the first time when the cutscene finiahed but I went down there again no sweat. There are alot of glitches in this game that can get really painfully annoying. Right now the only thing I can suggest is too just start again, you'll keep your level and you know the route

" your going to take damage you just got run to the right  and go up really fast and when you start going left u can get into a super run and do a short jump to fast run up the elevator shaft. I did this with 200 health, so it shouldn't be a problem "