Q: Honda odyssey transmission stopped responding.

It happened about a week back, the car transmission seemed to slip a few times when I was driving in the morning. Later in the afternoon the slip became more frequent and finally the car stopped moving. I tried stopping and restarting the engine, which seemed to work for the first few time but that too was only for about 50 yards or so, and after that it stopped working completely. Now if I shift the transmission to "drive", it doesn't move, instead it very slowly goes backward. I want to know the problem why this is happening and whether it will be worthwhile to repair it since this is an old car.

My car has 190000 miles.
My car has an automatic transmission.