~2 wks mild pain in R shoulder. Pain got much worse when arms above head pulling shirt off, now sharp pain in shoulder lift arm some ways. Ideas?

Rc tendinitis or... Bursitis. You most likely flared up your rotator cuff. As a result overhead activity hurts because your rotator cuff bangs against your shoulder blade (acrimonious) and causes impingement. Limit your overhead activity, get on some nsaids for a few days and Ice. If. It better you might need some guided PT or a cortisone injection. .