Dont know where else to turn

Rebecca
I have had leg pain for almost 9 years now. It is located mostly behind my knee and up my hamstring to about mid-thigh. Never got injured or hurt it (that I know of). I was a dancer and the pain began slowly during junior year of college when my dancing slowed down. 
What I have done or who I have seen over the years: physical therapy twice, mutiple MRIs and scans, four orthopedic surgeons, two neurologists, massage therapy, chiropractor, accupuncture, yoga/stretching, sports doctors, overall wellness specialists, cortizone shots. Im sure there is more I am forgetting.
Very little provides relief and a lot makes it worse (stairs, bending or straightening my leg...cant run or walk fast). 
If you have any ideas or suggestions, or questions, please please please let me know! I am scarred that when I do have kids I will be limited to what I can do with them.