Twice rebuilt still not fixed transmission

HELP! I have a 2004 GMC Envoy. About 4 years ago I unwillingly ran over a boulder that was placed in the middle of a winding back road. It cracked my transmission pan, and stripped my fourth gear. I had it rebuilt, only to have issues a year or two later, backing up hill, as well as shifting and idling. So I brought it to AAmco, and they said that the first rebuild was horrible, and that they would do it better. I then had it rebuilt again by AAmco. Now two years later I am having issues again. No one seems to know what’s wrong. The car’s service engine light comes on after driving for an hour or so on the highway. When I come to my first stop after exiting the highway, the car jolts forward as I start off from that stop. The car continues to slam into gear until the car rests. Also my transmission fluid gets dirty way to quickly. I am changing the transmission fluid every other oil change. I don’t know what to do… I don’t have the money, or the time to keep messing around. Any ideas

The diagnostic reads " transmission component slipping "

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