I have a manual trans so someone that knows the 4eat will have to verify but, it sounds like your center diff/clutch packs are dead. What is left of them is engage until you hit the brake and it is stalling the engine but the ECU is trying to compensate.
The auto setups changed a bit over the years and I do not know the specifics nor do I know how to verify. How does it turn in a parking lot/sharp corner?
Peace,
Greg