Sounds what I just went through. My pain started in the lower back, right side, and then progressed down as far as my knee along the back of my leg. I tried epidurals, PT (useless), but finally had surgery three weeks ago. Still recovering, but the surgery appears to have worked since the nerve pain is gone and only a little soreness near the incision remains.
If you want what my doctor called a "durable" solution, surgery appears to be the only option.