Get to a doctor ASAP. I had a slightly torn left shoulder rotator cuff from throwing snow balls at a tree with my son (stupidly, trying to re-live little league glory days when I was a pitcher); I throw lefthanded, golf right handed. I lost a year of golf in the early 90's because I was too stuburn to go see a doctor right away. After a few months of sleepless nights, I couldn't take it anymore. See a professional .