I am no doctor but i used to suffer with stress points in my body and in particular on my shoulders.
I was told it was caused but being tense around that area....even though u dont notice your doing it. Its tense for that long that it builds up into pain. Good massage and heat along with meditation to learn your muscles to relax will hopefully benefit you.
It's worth a try....if meditation relaxes u..u may notice over time the pain will decrease.
Let us know how you get on and im pleased to see a fellow scot here.