Shoulder injury! what should i?

[i need som help please]

Alright so i was fooling around with a buddy of mine, wrestling then i'm not sure what motion or position my left arm was but all i remember is a sharp pain. For a lack of better words it felt like my left shoulder lost its strength like i got hit in the funny bone. It was a weird sensation. I can still move my arm up and down but its sore in certain positions and when i reach for the skies my rear delts hurt. Its sore and i want to crack my shoulders like how i would crack my knuckles. Well if anyone has any idea of what it could be. It could be great help. Can it be subluxation? tendon or ligament tear? Its definitely not dislocation i think. What can i do to make it better? ice and hot treatment? PLEASE HELP!