What Causes Deep Pain Between The Shoulder Blades?

im 55 yr. old with alot of health problems ihave artery diseas and stents in both legs have miney strokes also hige blood per diebetic ,and more what i need to know is for two or more mounths now i have siver pain deep in between my sholder blads it dose not stop and stays in same place i hurt so bad that i almost go to hospitle every nite, cant sleep due to this and when i do im never feel that it is very sound i wake most every hour through the nite .