'Popped' Shoulder from Baseball Swing

Hey guys,

Sorry if this thing has been asked already. I was playing softball yesterday and after a swing on a low pitch, my left (leading) shoulder felt like it “popped” and its been very sore. This has happened a few times before and I have been doing some shoulder rehab work on and off, usually when it hurts a lot. Right now, any internal rotation hurts like a bitch. I can feel my shoulder ligaments grinding together. Not sure if this is related, but I think I have also some sort of rhomboid strain, which I’m getting checked out next week by a physio.

Any help on the issue would be much appreciated, especially in the self-help department. Thanks