I've Been Having Burning Pains In My Shoulder Blade. It's

I've been having burning pains in my shoulder blade. It's still very painful, but now it also feels like there is something moving under my skin when I move my arm. The bubbling is new, but I've had the issue with my shoulder blade burning, and hurting for a while. Sometimes if I move too much I can't use my arm for several hours. I've tried otc's and ice and nothing helps. What is going on with it?