Tranny Issues

I have a 1992 SVX AWD, it just turned 103k and runs like new, I was driving down the highway the other day and the car made a jerking motion and started making a humming sound, I pulled off the highway and then the car would go in drive, making a whining sound, but no reverse. then when trying to load on a rollback to move not damaging anything else, the car even with the shifter in neutral was locked, car wouldn't budge! Does anyone have any idea what the problem is? Obviously tranny issues of some sort, but I dont want to spend huge money on a tranny and not need it! Please I hope someone can help me!!!