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.
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.