Diesel Bombers - HELP! Auto Stuck in high gear and wont shift. lots of smoke

Truck info - I have i 2001 cummins 24v AUTOMATIC, 140k miles, new engine, Fass, DDP 50s.

Truck Problem :argh: - I was going bass fishing yesterday and it drove just fine to the pond. but when i left it had no power and was dumping smoke. it feels like its stuck in 3rd... or a higher gear then first. if i go from a stop it takes forever to increase RPM and blows tons of smoke like there is alot of load. HOWEVER if i manually put it in first or second (auto trans) it relives the problem.

Scenario - Im at a stoplight and i take off with no power dumping tons of smoke... Like trying to launch a manual in 3rd gear. So to make it home without painting the road black i had to manually put the truck in 1st then shift into drive when im at the top of first... and evin then if i try to get on the freeway it will not go into the last gear. it is stuck in one gear unless i manually shift it to first or second.

Diagnosis so far - i figured someone would have had the same problem as im having on here so i have been searching peoples threads and all i can find is people that are stuck in first gear and saying its a gear sylinoid or they are in Limp mode and saying its the TPS. SO i have decided to post my own thread and see if anybody could help me out with my specific issue. If you need to know more info just ask in replys. THANKS!!!!!