I had shoulder problems for at least 3 years but they have diminished in the last 18 months. Amongst other things, I had an MRI in Newmarket that showed a small amount of deterioration but nothing significant. For me, the biggest help came from Thumbs-of-Death (Nigel Hudson - Albion Hills Chiropractic), our sports chiropractor in Bolton who inflicted horrendous pain and liked to stick his knuckle into a particular spot in my upper back. OW!
I expect that much of the correction will be at a chiropractic office. Visits so far have yielded some near term benefit. It did include some brutal poking in muscles in the back.
I'm more concerned about the referred (I believe) pain in my right hand and periodic short term numbness in the whole left arm. While I don't think it is related, my dad now has very little function in his right hand so I don't want to make too many assumptions about the underlying cause.
You have pain on the right and numbness on the left? That does sound like more than a shoulder problem. I never had referred pain but I would often wake up with numbness in my hand and sometimes it went farther up my arm.