Methadone anxiety question?

I have been on methadone for a little over 5 years. At my highest dose, I was taking 105 mg a day. This was the Methadose.(the liquid). About a year ago, I decided I wanted to detox. At first, I came down 5mg a week until I hit 25 mg. Then, I came down 2 mg a week til I hit 17mg, then tapered down to 1 mg a week. I am now at 9 mg and I’m getting nervous about going lower. I asked the nurse today if 9 mg really did that much for you. From what she said, at higher doses, your body can store meth in your fat cells, and you could go for a day or 2 without taking any meth, and only have slight withdrawals. At 9 mg, there isn’t enough for your body to store. Then I asked her if I could just stop at 9 mg. She said people are different. Some are okay jumping off at 10 mg, and others have problems.
I currently have no cravings, and I’m not experiencing any withdrawal symptoms. A couple times like around 20-22 mg, I felt a little withdrawal, but I just held my dose the following week, and everything was fine. I do suffer from severe back pain. I herniated 2 discs on July 3, 2006, and the following April, I had surgery. They had to put 2 titanium rods in my back and removed the discs. My pain is gradually getting worse as my dose gets lower and lower. After my surgery, they gave me dilaudid, but I was only on that for about 3 weeks post op.
My anxiety comes from me not knowing what I’m going to do about the pain. My surgeon said that I’ll probably eventually need another surgery because the discs directly above, and directly below my fusion have to work twice as hard because my 3 of the vertebrae in my back are locked due to the previous surgery.
I asked the nurse today how much analgesic effect 9 mg of methadone has, and she said hardly any. She said that the effect may last up to 4 hours. I don’t want to have to take any more narcotic pain medication. Thats what started me on this whole rollercoaster ride anyway years ago. I’ve tried ibuprofin, celebrex, tylenol, and I even have a TENS unit and an Interferential stimulator that my surgeon prescribed to me. The TENS and IF work when I have them on, but as soon as I remove them, the pain is there again.
What can I do about the back pain????