1995 dodge ram transmission problem please help?

[Glen]

i have a 1995 dodge ram 1500 with a 46rh transmission, one day the transmission started slipping and then it just would move,, so we changed the fulid and filter and it work great for one day then it back to slipping in and out of gear, and some times when we stop it dont want to move then it gos into gear please help could it be a sensor