Welcome motorman! Sorry to hear of your pain struggles. At least you have physicians that are on your side. From my experience, it was the insurance companies that tend to muck up the works. A friend w/ MS suffers with Trigeminal neuralgia and has a difficult time knocking down the pain. I have sacroiliac pain myself that at times makes getting to sleep difficult. I'm currently not taking anything for it, as it tends to come and go. I really need to get it checked out, as I'm not sure if it's MS related or a result of an old sports injury. I'm also very sensitive to pain medications and don't tolerate them well.
Have you ever had a physical or occupational therapist look at how you're walking/moving? Sometimes how you walk or even do things like sitting can contribute to the pain quotient. When I was first diagnosed three years ago, my vision was terrible and getting around was difficult. I did a short PT stint to help me re-learn to walk. My gait is much better, though I still stumble and trip frequently. You may also want to investigate alternative therapies like acupuncture, which is supposed to very good for pain management. No need for you to suffer with it! Best of luck to you.