It sounds like this is something that developed over time, and may be from aging, only you may know. I would stay with the physical therapy over surgery, which almost always leads to PT. When the therapist told me, that pain is from an impinged rotator cuff, and it would eventually lead to a tear and surgery, I listened. He want me to start with light exercises, for that condition and come back in a few weeks. He said, it would help. It took about five months of daily exercises, mainly at home until the muscle group strengthened and thickened to protect the arm bone in the shoulder. The pain gradually disappeared. I would opt for a second opinion if in doubt, and PT over surgery. Some like to shoot more than others, some find mixing exercise with shooting is better, I'm in the latter group, especially as I get older. Good luck.