2005 Chevy Monte Carlo fuel

For the last month sometimes in the morning when I wetn to start my car I would have to keep my foot on the gas in case it decided to start to stall out. This did not happen every time and once the car was running for about 5 minutes I did not have a problem for the rest of the day. Tonight after I had been driving my car for about 1 hour, I stopped to get gas and when I tried to start my car, it would turn over but not start. I tried several times to start the car and it started a coulple of times for about 10 seconds, but it would not remain running. It would almost backfire and it sputtered at a very low rev but not to the point that it would remain running. I also had just filled the tank up with gas and had put in a bottle of fuel injector cleaner before this happenned but I do not think this would be the problem. I believe it may be the fuel filter however I am not sure. Any help would be apprieciated.