since the trans backs up per yur post...
that tells me the pump is working enough to move the car.
the converter is transfering power to the trans via the input shaft.
direct clutch is operating since the car backs up
No forward gears in any shifter position? = 1 , 2 , 3 ?
That makes me think there is a problem in the forward clutch pack or the roller clutch in the back of the case
Dont worry how old you are... it is the mileage on your body that adds up.