My truck broke down while driving. The engine stayed running but when I hit the gas it wouldn't accelerate.?

my truck broke down while driving on the freeway. The engine stayed running but when I hit the gas it wouldn't accelerate. I pulled over to the side of the road and turned it off. I then started it again and it fired but when I tried to accelerate it moved a foot or so and that was it. I then turned it off again and tried starting it again. This time it wouldn't fire any suggestions?