sissy

Hi I got in my truck to leave . I tried to start it and it was like it was almost dead, but it started. When I started driving it I couldn't get my speed up even when I had it to the floor. The rpm was where they was suppose to be at 20 mph. So I turned around come back home. Turned it off and started it again and it started right up. But still had same problem. I recently had to put a fuel pump on it and they didn't change fuel filter. I had the filter put on a few days ago. please help tks in advance