I have a 1995 Ford Explorer, and it will not accelerate?

As I was driving back from school is was fine, and a little whiles down it started to shake so i thought it might be my engine about to lock up but i knew i had oil in the truck. So I run in to this gas station to get a small quart to top it off and i started driving again, still a little shakey and had a hard time accelerating. I got to this stop sign and it started shaking again and trying to cut off, then i tried to go and it wouldnt move. I got the car up to 40mph then i started creeping inch by inch but still not moving like it was supposed to. I don't know what it is.

Its broken

Probably your transmission. Is the car nearly red lining at 40mph?