And. It's been four days, and there is less pain. The exercise still hurts, but not as much, and this morning I was able to move my right arm more easily than I have been. Of course, I've been avoiding putting my right hand above my shoulder (just try washing your hair that way!) and I switched from a shoulder bag to a backpack, so that had to help, too, and I'm using my left arm more for the same reason.
Whatever it takes - it's working. I'm glad.