Hey guys Long time no talk! my transmission is acting up

[cheappc]

I have a 2004 x5 3.0, if you search my posts, I posted something the day before I bought it and right after I bought.

Its been great since I fixed my window regulator, I bought it with 55,000 miles and it now has 71,000 miles.

Ever since I got it i have had a weird issue with my transmission. After a lengthy drive, or going uphill towing my boat. My transmission feels like its "slipping". Just like 2 weeks ago, I went to Laughlin Towing my boat, we arrived fine, then I drove about 1 hour and a half to Las Vegas, as soon as we got to Las Vegas, and we reached a stop light, my transmission totally slipped, we put it in gear and it wouldnt go at all.

I thought maybe it was overheating, since it has happened to me on a couple of occasions I just turned it off, waited a second, and restarted the car and everything was back to normal..

It feels like my transmission is about to die right? or please let me know.. thanks