I would really push to see a specialist on that if you haven't already, my wife spent ~6 months trying to recover from an AC joint injury through physio before they realised it needed surgery. A couple of months later it was 90% recovered.
Only happened last night so all slinged and drugged up, and due to see NHS consultant (or their lackey) next Monday. I do have private cover though so I do have the option to see a specialist privately if necessary.