radiotech

I'm looking for some help. I have a 1994 Eg hatch with a B20b block, far head and trans.

I down shifted on the highway today and suddenly had no acceleration so I pulled over. Car will not move in any gear now. Engine running fine and revs, clutch pedal is still firm and not leaking any fluid, transmission shifts right into gear, but it won't move in any gear. I dont hear anything "expensive" when I rev it in gear either. No sounds of broken clutch or grinding metal. I looked things over and it looks like the passenger side drive shaft is seperated from the transmission some. I can grab it shake it around and its leaking gear oil from wear the shaft goes into the transaxle. I understand this is an open diff so I assume an axle being detached would cause the car not to move?

How do I go about testing if it's the transmission? Can I just reseat the axle or do I have to replace the set? What would cause the axel to move out laterally like that? I bought the car already swapped so I suppose it's possible the person who did swap it didn't use the proper axles for the swap, I'm not sure