My 2011 Yukon wont move.

I have a Yukon denali, all wheel drive with an automatic
transmission. When placed in gear it will move for a few
feet forward or backward and then stop pulling. The
transmission is still good. I was stranded on the side of the
interstate and when the wrecker came it was a flatbed. The
operator drove my Yukon right onto the steeply inclined
flatbed. By the time we got home with the vehicle we
started it, it reversed off of the flat bed and drove right up
the hill in my driveway and just stopped pulling. You can
turn the truck off and restart it and it'll move for a few
seconds and then just starts revving up. Please help!!! Any
info will be greatly appreciated!!!