Okay, I asked my teacher at school today for some ideas. The main thing is you have no reverse and no forward gears, which means the low forward clutch is not engaging. The low forward clutch is used for both forward and reverse gears.
Lots of questions for you.
1. When you get it off the ramps, make sure you didn't overfill the transmission. If you overfilled it, it can cause the pump to die.
2. Did you buy an OEM filter? If not, get an OEM filter. Aftermarket filters can be clogged straight from the factory which would cause the fluid to get get pumped and then you would have no fluid pressure to engage the clutch plates.
3. Are you sure the o-ring on the filter is properly in place? If the o-ring is not in place, this can cause fluid leakage, again starving the pump, preventing fluid pressure from engaging the clutches. The leakage would not be present outside of the transmission. It would be internal.
4. When you put it in gear, can you hear the solenoids clicking? If not, the solenoids may have gone bad.
5. Again, make sure the fluid is not overfull, but also make sure there is enough fluid. Not enough could starve the pump and again, no fluid pressure, no clutches.
If none of this fixes the problem let me know.