I've gone through the same with upper back pain that sometimes radiated to my arms. No therapy seemed to help and after 2 years it was hard to see how it could

I've gone through the same with upper back pain that sometimes radiated to my arms. No therapy seemed to help and after 2 years it was hard to see how it could ever get better. Eventually I got into a multidisciplinary pain rehabilitation program and I made a full recovery in a couple of months. It turned out I was constantly tensing my upper back muscles and arms without noticing it. Never underestimate how much muscles can hurt if they don't get the opportunity to relax! After I relearned the habit of keeping those muscles loose the pain slowly subsided. I had to gradually build up work activity again though. In the beginning the pain would return when I would increase my activities. When you have pain for a long time there is also sensitisation of your nervous system so you have to take it slow. I don't know if muscle tension is the cause in your case, but it could be a factor. Either way, if you have the option to enter a multidisciplinary pain management program I would highly recommend it.