Patella Pain Returning

About a year ago I had major knee problems which I never got a clear answer for, doctors gave me different answers from quadricep tendonitis, IT band tendonitis, and jumpers knee due to a lack of flexibility or overuse. The pain was directly on top of my patella and was excruciating when I put strain on it, squat or lunge.  As a result I had to stop sports all together for my winter and spring seasons of my senior year to do physical therapy that did not make much of a difference. Instead I took a year off doing nothing with my legs and that actually seemed to solve the problem. After a year though I have finally started to retrain on it, lifting and running to prepare for an upcoming lacrosse tryout at college. As a result the pain is coming back in the same place but I am continuing to work on my flexibility and leg strength to counteract it. I still don't know what exactly the problem is and I don't have much faith going back to a doctors office or physical therapy that doesn't really help. Does anyone know any way I can actually treat this?