Bad transmission

I was driving the vehicle and stopped at a red light. When the light turned green the vehicle would not move.
It had to be pushed out of the intersection.

There was no tranny oil on the ground below the vehicle when it stopped. There are no metal shavings in the fluid. Vehicle will not move forward or reverse.
Shifter stills shifts ok forward and reverse and the vehicle feels like it wants to move, but nothing.

This vehicle has the V6 with auto trans.
The motor runs fine. I changed the timing belt about 5,000 miles ago.

I am stumped. Did the torque converter die, or is it something else.
I know there are some kind of sensors on this tranny, could that be it.
If it is not an expensive fix, I am going to fix it as I am on a tight budget right now.