Jackie

The car was overheating when i would stop at lights but was cool while driving. Took it to Firestone and they replaced the thermos, gasket, did a radiator flush and changed the serpenine belt. Two days later the car was still overheating and now when i try to push on the accelorator the engine revs but the car barely moves forward. The first time it happened i was in the middle of an intersection so i pushed the petal all the way to the floor and the car went forward but wouldnt go faster than about 30 Mph. after i was in a safe spot i pulled the car over and called a tow. now the check engine light is on. Any suggestions on what the problem might be are appreiciated.