Need some help

Ok so I was just out in my garage hitting my punching bag a couple days ago and now my shoulder is hurting and my grandma thought it was a pulled muscle which it probably is bc I can still move it but it hurts like hell. And today at school one of my teachers said that on the top of my hand around my pinky looked like it was bruising and my pinky hurts like crap when something touches it. Anyone have any ideas on what I should do?? I have a sling I could put on but idk if I should. But my real question is should I put a brace on my wrist??