No start

Truck all of a sudden, I could barely start and had rough idle, press on gas RPMs go up two and then drops and if I let off gas pedal which I pump it will shut off. Truck has very low power and does not seem to be shifting up in gears, had to ride the brakes and gas just move it a short distance. It also seems to be getting hot quickly. I had to move the truck a couple of times due to parking situations. Now it won't crank or start. It has a good battery replaced front fuel pump and filter and reached distributor cap and rotor. I don't have much money and I have to move it, or some jerk will tow it. Any help please I've only had it a short while and I think it sat for a while before I bought it. I had no problems until I left I left it unattended one evening, looked like some got into my cab because my passenger foot panel popped off quite a bit don't any of this would affect it but thought I would mention it anyway. The truck listed above is an Xlt Lariat.