Has anyone been diagnosed following an initial hand condition?

Hi all, I don't know if any of you can help. We're based in the UK and have been going through various NHs routes for the last three years. My husband has been having chronic pain in his hands for over three years now. He had an initial injury to his wrist and carpal tunnel syndrome which was operated on about a year ago but he's still experiencing constant daily pains. At first we suspected he'd got arthritis, but there are no visible signs of that, nothing on the x-rays etc. He mentioned the other day that he also sometimes gets random flashes of pain in his feet and so now I'm wondering if fibro might be a potential cause? He did have nerve tests about 18 months ago and they came back as normal, but the pain in his hands in particular has gotten worse since then. The last appointment we had with his hand surgeon we were told that there are no visible signs of injury or any health condition as it was said that the pain is basically in his head. We're at a complete loss as to what to do now or what to try next. He can't carry on untreated. He isn't sleeping, his mental health is deteriorating because he's had to give up so many hobbies. He says he feels useless because he's unable to help me around the house with chores or caring for our dog. I hate seeing him so upset and in so much pain. Any advice on what we can try next or where to turn would be hugely appreciated. Or if you have a similar story that you can share with me, I'd massively appreciate that.