1997 Pontiac Grand Prix Car Stalling

My car (supercharged 3.8L engine) has seemed to be running fine, until a week ago. We had a big snow storm, so I let my car sit 2-3 days while it was quite cold. Then the next day it rained A LOT. On this rainy day I attempted to start the car, and it wouldn't turn over. Next day I tried again, and I got it to start but it stalled out after a matter of seconds, varying btwn 3-30sec each time it started. I checked the oil and put a quart in to fill it up. I ruled out a battery problem, it did the same thing with my battery connected to my friends battery.

After it stalls, there is a sound from under the engine like a pump running for a second, then there are a couple lights coming on. "Service Engine Soon" the battery light, and the 'low oil level' light (which is why I checked the oil). The car is due for an oil change which I was planning to get done soon, but I can't even get it out of the parking spot.

Could this be moisture in my gas? Partially frozen gas line? PLEASE HELP.

**note: my car is parked outside and exposed to the cold, but is mostly covered by a cantilevered second level above it, so it gets snow and rain that blows onto it, but not massive amounts.