Try Curcumin. Used Curcumin Pro with good results. Not an NSAID so no bleeding gastric issues. I take about five a day. Helps. Have arthritis also and have been told the eventually I will need a shoulder joint replacement replacement. That was over ten years ago. PT, and the standard rotator cuff exercises help a lot. Trick is you stop doing the exercises and the pain comes back. Did not stop. Also my chiropractor has helped with stretches. YMMV. Surgery a LAST resort.
Good luck.