What did i do to my shoulder?

I don't know when i hurt my shoulder but it hurts really bad. I can' lift my arm above my head. It hurts through the front and back and there is some swelling. It feels warmer than my other shoulder also i have tried ice and that hasnt helped. What could be wrong? Should i wrap it? I dont really want to tell my mom because she will make me go to the doctor and i have a softball tryout in a couple weeks and i want to be able to play.