Check engine light/throttle body light?

The car first started having problems with turning off and back on for a split second while driving. It would usually happen when using more power, for example going up hill or when accelerating. After a week I began to notice that every once in a while, when accelerating it would seem more sluggish than normal. Not so much power. About a month later it started to turn off (not shut off) at stop lights, stop signs, or low speeds under 15. And sometimes while it did turn off, the car would shake, and the throttle body light would come on. This, and when it tries to turn off while driving, would be the only time the throttle body light shows on the dash. When I turn the car back on, sometimes it will run fine until the next stop it chooses to die at. Sometimes it will delay a bit and jerk forward and start driving. And sometimes it will turn off a couple times before running fine. Also, sometimes the car will be running fine for a couple days with no lights, until it will finally shut off and then the check engine light comes on after turning it back on. After the light comes back on, it usually starts to act up.