My car will crank, but then immediately dies. Solutions?

I have a 1997 Volvo 850 wagon, and the last time I drove it, it began to shudder at red lights, but it made it home. Then, the next time I tried to crank it, it immediately died. The engine would turn over, even let me rev the engine, but after a few seconds, would sputter out and die. I'm thinking maybe it has to do with the quality of the gasoline (maybe somehow got water in the tank?) but I really have no idea. I don't want to take it to a mechanic unless absolutely necessary, because I would have to get a tow truck, etc. Any ideas?