"Going round in circles"

I have been going round in circles for months, have serious pain in my left kneecap. I have been referred to the specialist orthopedic department to be told that they cannot find what is causing the pain and instability. The left knee keeps locking and whilst visiting the physiotherapy department on my last referral, I was told that the pain was "all in my head". I do not recommend this hospital to anyone who has serious problems as you will be messed around. In the meantime the problem is worsening and starting to affect every aspect of my life.