What can I do to treat my thigh pain for past 10 years?

Depends on its cause. First it'll need to be diagnosed, possibilities include arthritis of hip, or in lower back, where there might be a pinched nerve. These are the common conditions; others would include thigh bone lesions or in the soft tissues of the thigh itself. Once diagnosed, then treatment could be initiated. I am unable to provide you with any other advise till one knows the results of exam & tests.