tranny problems??

I'm new here, but i've been all over the internet tryin to get some answers...I have a 1990 n/a automatic supra. The tranny has messed up like not going into 3rd gear sometimes, but that stopped as the weather got warmer. Well recently my sister jammed into drive when it was still rolling back fairly fast and it didn't sound good. Not too long after I drove it it started smoking, but not out of the tailpipe. Something was gettin on the tailpipe from around where the driveshaft comes out and burning from the heat of exaust.Then it started whining/screaming when I got faster...wondering if this might be the torque converter or is the tranny gone?