Could it be a muscle adhesion or a knotted up muscle that's pressing against the nerve? If you can pinpoint the area, maybe massage with something like a rolling pin will help the muscle return to normal. Sounds like you'd have to work it daily, in a kind of 'rolfing' way, to break it up...if that's the problem. Also, a heat wrap like Therma-Care (x-large for back and hip), wrapped around the thigh overnight might assist in relaxing the muscle, they stay warm for a good 10 hours.
"We can judge the heart of a man by his treatment of animals." ~Immanual Kant~