Level 1 MCL tear healing process?

A month and a half ago I was running down a sand dune, went to turn, twisted my inner knee and heard a pop. My symptoms the following morning: deep sore stiffening pain, unable to fully extend, sharp pains if attempting pivot, swelling of the inner knee. I went to a doctor who then sent me to an orthopedic doctor. He said to wait it out a couple weeks, probably only a ligament rather than cartilage or tendon. Symptoms persisted. The sharp pains started to lesson. Still very unable to extend leg two weeks later so I returned to the orthopedic doctor. ( By this time it had been nearly a month since the injury. ) He sent me to get an MRI. He read my results to be that I have a level one MCL tear. He said i should ride a bike and do aquatic exercise. One friend is telling me I really need physical therapy in order to work my leg back to the point where I can extend it fully. The doctor did not mention this. I am also a little broke from all the doctor bills. My questions: Are there certain stretches for my situation? Are there things I can do to speed up the healing process? Is walking on it bad, at this point do I need to be resting it a lot still? (My doc said at this point it is just up to the amount of pain I can take) At what point should I be worried if I am still unable to extend it? It is still very sore, stiff and a little swollen. Are ligament tears meant to heal on their own? (My doc said it may take from a month to four months)-- any personal experiences with this on what to expect? Thanks so much.. any knowledge and personal experience is greatly appreciated! Thanks!