Shoulder and neck

hi im hoping someone can help me i do weights but nothing really over the top heavy, my problem is a sharp pain in my shoulder but only when i pull my arm back, the pain seems to be on top of my shoulder. Ive rested it 4 a while now and although it seems to have eased it wont seem to go, ive tried ice and heat and after woulds it feels really good but only for it to come back. I also get alot of crunching around the neck area when i bring my shoulders up and when i twist my arm gently i get lots of clicking, ive rested for a while now and im starting to get a bit restless so hope someone can give me some tips. thanks in advance for any replies.