So, the car will not move in any direction with the wheels on the ground? Perhaps the torque convertor has failed, or perhaps the fluid pump within the tranny died. It's also possible that one of the shafts within the tranny has broken, although this is less likely.

In conclusion, you've moved beyond DIY territory. You should take it to a transmission specialist.

Have you checked the shift linkage to determine whether it is still firmly attached to the transmission?