ChvySub runs great then low idled at stop light w/no response to gas.

What is your question?

My 2002 suburban runs fine. all of the sudden im stopped at a light and the rpms drop low. I tried to press the gas pedal to rev the rpm's and keep it from stalling and no response to gas at all. I smelled gas. I could not move the truck. I turned it off for two light cycles and tried to restart it. Started fine and drove perfectly for a few miles. Waited at a long light and problem happened suddenly again. Thought it wouldn't start after i turned it off this time but after a few minutes it started and i made it home. Any ideas?