I'm not sure how your insurance is but would you be able to get a referral to a PT or AT. The symptoms were a fair bit different but, back in 2003 when I was dealing with knee soreness, I messed around with doctors for most of the year before getting a PT referral. I ended up with an AT (all the better in my opinion) who instantly diagnosed my “knee injury” that doctors had diagnosed as every “itis” in the book as a pulled hamstring. She had me back to normal in no time. Maybe a PT or AT could find something that the doctors might overlook? Unfortunately, I can't refer you to the AT I had because she works for my employer's employee health division (unless we are both employed by the same company without knowing it).