If sleeping on the back is more to your liking, put a pillow under the knees. If the leg becomes weak, if there is numbness in the groin or rectal area, or if there's difficulty controlling bowel movements or urination, see the doctor without delay. These signs can indicate permanent damage to the nerve unless the pressure is removed quickly. A person can do any activity that doesn't aggravate the pain. Your pain has lasted quite a long time.
Most people recover in one to three months.
Surgical correction, infrequently needed, might be the answer for you. I am sending you the report on backaches and back problems. It gives you other tips. Box 5539, Riverton, NJ 08077-5539.