I can't still walk after 3 months from ACL reconstruction. Can I gain back normal knee movements?

I am 17. After a car accident, I torn my ACL and PCL badly. The doctor did ACL surgery and plastered my knee for 45 days afterwards. My knee is very stiff and I can't bend it. The physical therapist believes that it has to be bent under general anesthesia. But I don't want that. Does anybody know if it's possible to have it bent through mere physical therapy? The doctor believes that after, the knee bends, I need a PCL surgery too. Can anybody tell me if I can ever regain my complete knee movement back?