I had an L4/L5 discectomy and decompression 5 weeks ago today. I was back on a Turbo Traner within a week, so I count myself very lucky (plus a little stupid). It took me a few weeks before I could sit properly, but strangely cycling causes no pain. I spend most of my time standing or lying down, but to be honest it is a dream compared to my pre-surgery state.
A lot of my friends have had similar operations, or fusions and so far it is a 100% success rate for those of us who were lucky enough to have private insurance and 100% failure for those via the NHS. I am not sure if this is luck, but I am certain private gets you the best surgeons and exactly the right treatment when you need it. I tried something called IDD before my surgery, but unfortunately although bring pretty expensive it did not work.
I really feel for those who sound like you have it much worse than I did, I know how you feel, but what I can say is don't give up, I had many days pre treatment that were horrific when I thought that it would never get better. I doubted if any treatment would work and was wondering if the next 40-50 years would be driven by pain. Now I feel a completly new lease of life, I am not 100% fixed and not sure if I ever will be, but wow things are great.
Fingers crossed for all of you that you get your breakthrough too.
P.S. There is still knitting to look into.