Don't trust the diagnosis until it is for sure! Those doctors, I don't trust them at all anymore after seeing specialist after specialist. They just shrug their shoulders and send you out the door with a perscription.
To get through those tough times, I hate to say it, but ibuprofin in massive amounts (*disclaimer, take only with perscription, which I had). That stuff is harsh on your stomach so needs to be taken with care. I'm tellin' you, when you go through your first 800 tablet bottle, you know somethin's not right. When I was at my worst I was taking a total of 1600 mg a day (800 in the morning, 800 at night).
Actually, since I stopped running so much and started martial arts and yoga, I haven't had much joint pain. Running is really jarring on your joints and if they are already inflamed, then it just makes it worse.
It's funny, but I stopped squatting years and years ago in high school because of knee pain, but now that I've started again, it has strengthened my knees and made them feel so much better. I think the weight training has really helped. Up to the age of 25 it can increase your bone density