Knee pain in both the legs. I would be!

Hii, Iam having an issue of knee pain since 2 years now. The pain increases if I apply pressure on my knees like during squats, walking down the stairs, running,etc. It also pains while bending the knee. There is also a small hump just below the knee cap which if I press or even touch, it pains badly. I have got the X Ray done, MRI, all blood related tests and shown it to multiple doctors even in AIIMS Delhi but the doctors have said it's normal and they could not find anything in my reports. I am part of the armed forces and regularly play badminton because I need to keep myself fit and within weight limits. I also used to run earlier but now I can't because of the pain. And because of that iam putting on weight which is aggravating my problem I suppose. I would be thankful if anyone can advice me of how should I go about this problem. Regards.