1996 Buick lesabre transmission stops working after 5 minutes

I was driving my Buick LeSabre 1996 down the road and all the sudden it’s shuttered and I lost all the gears. I pulled over shut it off starting it up and went through all the gears and it still had nothing. So I let it sit for about 10 minutes start it up and it worked fine again for about 5 minutes. It’s full of fluid and does not smell burnt. I’m at a loss because I’m supposed to be making a trip to California from Florida to see my sick mom in less than three weeks. Any suggestions would be great. Financially I’m not able to place the transmission so I’m trying to find other ways of fixing it