tonight i was driving around town and i stoped at a light then made a turn as soon as i got out of the turn i started to accelerate not hard at all and all of a sudden my gmc defeuled so i got off the gas and the check engine light came on after that the truck would not shift out of first so i had to drive home doin about 30 in first gear
ANY IDEA ON WAT HAPPENED TO MY TRUCK only has 14k miles on it 04 wit allison tranny only have intake no programmer or anything

You have to retreive the SES code,best place to start.

All will be fine ,I'm sure

Does it work OK after you restarted the engine? I'd take it to the dealer and have them scan the codes.