Hi Adrian,
While fibromyalgia can cause what would normally be relatively minor and temporary pain to spread and last for a much longer time, this sounds like a bit much even for FM – although if a nerve, muscle or tendon was significantly damaged it could take awhile for the pain to go away even after it healed. I wish I could tell you what the problem might be, but I just don't know. I would definitely call your doctor back and let her know it's not getting any better. It seems she should start trying to find out exactly what happened.
I'm sorry I can't be of more help. I do wish you the best as you seek an answer from your doctor. – Karen