Bike wont stay running

I've got a 1998 Suzuki GSXR-600. Everything was fine and it road fine the last time I road it. About 2-4 weeks went by and i went out to ride and it wouldn't start well...when i finally got it going it wouldn't run for s**t. Had to keep the choke on and had the throttle response was extreemly poor. I've only got about 10 or 11 thousand miles on the bike and i'm not sure what is causing this. I've checked the air filter, changed the plugs, but this is to no avail. Last time i road i had filled up with gas and road about 12 miles or so before returning home and shutting it off. Bad gas? Fuel Filter? Anyone have any other ideas.
Thanks,