Sounds like you might have torn something, or dislocated something. I would see a doc.
Wow! Sudden jerking movements often cause the muscle to 'rupture' or pull off its attachment. It just happens. A trip to the doctor may be a good idea. In the meantime, IF it were my body and the NSAIDS were not working, and the pain was severe I might consider the Urgent Care/ER route, esp in light of the pain breathing and the scapular protrusion. Good luck!