how long will it take for a mcl strain to heal? I have had extreme pain and some swelling for over 5 months.

I fell about 5 months ago.  About a week after the fall my knee started hurting.  I was not worried because I have always had knee issues.  I noticed a lot of swelling .  I waited about a month and there was no improvement.  I went to the doctor and had an mri.  They found a small Baker's cyst, and a sprained mcl.  It has been 3 more months and the pain is strong enough to wake me up at night.  i have a strong limp and cannot straighten my leg all the way without sever pain.  It is most painful behind my knee and on the inside, the part of my knee that faces my other leg.  My doctor says the pain is caused by chondromalacia patella.  A condition I have had since my teen-age years also confirmed by the mri.  the pain is different than the pain I have had in the past do due chondromalacia patella.  It is dull and deep and located in a different spot.  The swelling is also greater.  He says I am just going to have to live with the pain.  I am finding this difficult to due.  I am unable to ride my bike, hike, take spinning classes or any other activitie that I have been doing all my life.  This is making me miserable.  How long does the pain normally last?  Could my doctor be wrong?  What are the chances that the mri missed  a tear or something else? 

Thanks Lori