I Have Been Experience A Constant Dull Pain That Has

I have been experience a constant dull pain that has now escalated to a sharp spasm type pain in my shoulder. Sometimes it feels like it is in between my spine and my shoulder blade that goes up under my shoulder blade like right behind my breast and at the top of my lung. It wakes me up at night, my arm will go numb and nothing seems to help it. It is to the point that it prevents me from turning my head without pain. I am having 2 MRI's tomorrow.