Well, I would say it could be one of two general problems:
1. Clutch related - stuck linkage, fluid problem if it is hydraulic, etc.
2. Transmission related - broken/damaged shift fork, damaged gear, etc.
Sounds to me like it might be more clutch related, but hard to tell over the Internet. I would take it to someone who knows what they are doing.
I had this happen to a friend's car in college. The clutch cable broke and it was nearly impossible to shift. I had to drive it to the garage for her. What a pain that was. I hope this helps. Good luck.