Undiagnosed Hip and Knee pain

Hello, I live in Dallas and I have had severe hip and knee pain (simultaneously) for over 3 years now and have had imaging, surgery, and extensive physical therapy but my very reputable doctor cannot diagnose my pain. I've been to both the knee specialist and the hip specialists at TOA on Greenville and no relief. They said it is not a textbook problem and they keep just offering bursa and knee injections. I left the office in tears today after having another round of injections that typically last a month. I am 61 years and in very healthy shape and I can't even walk up a flight of stairs due to the pain. What do you do when the doctor cannot help? Prior to hip ligament/labral tear repair surgery I went to another very reputable doctor for a second opinion (Carrell Clinic) and he said the surgery seemed like the thing to try. It did not fix any of the pain. I'm at a loss as to where to turn now?