1999 Chevy Cavalier sluggish acceleration

Engine Performance problem
1999 Chevy Cavalier Automatic

Car driving fine, I stopped at stop sign, turned left onto gravel road and when I pressed the gas peddle it didn't seem to accelerate at the normal rate. Since I was on gravel I wasn't trying to get it up to high speed really fast or anything. We had recently just got gas so we added some gas dry stuff and it seems a little better at times. Has only completely died once when I pulled slowly in driveway but just doesn't seem to be running smoothly, with very little power to accelerate. Pushing the gas peddle down further has no affect on the acceleration. With a long enough stretch of road it willl eventurally speed up enough to shift thru all the gears. While in park the engine will rev up when I push gas peddle.