I wish there was someone who could massage a shoulder better but there isn`t. If you can`t move it, you might have some impingement which would be confirmed by an MRI scan.
JJ/Conn I have seen you say before that you don't like to waste the GP's time and that is admirable, but that is their job, to help each patient with all ills major and minor.
Go see them and ask for a Scan (or a Scam if they have one) ;-)