transmission

I am very confused. My car was was running very good. I had my back brakes changed by a shade tree mechanic and they were making a sweeking noise. The mechanic told me to back up fast and press my brakes. This is what I did, now my transmission is not working. I actually have to have my car pushed to get it going. Once I get started the transmission works fine, but once I hit my brakes it will not shift back into gear unless I get a push. Please help me I don't understand what's going on. I hope it's not the transmission because ford just changed that transmission 2 years ago

what year and how many miles?? my 92 wagon clunked when i dropped it into drive but it was fine exept that. But my 95 wagon slips like a motherfucker... doesn't help when ur friend takes it out, overheates it and brings it back pissin tans fluid everywhere.

My car is a 1999 sable ls. It's hard to believe it is my transmission, I am hoping it is not