Back pain across shoulder blades is the specific result of an uneven and sunken mattress and bed. Throw away the mattress and the bed and try sleeping on a hard surface like the floor.
In extreme anxiety and stress, the neck and shoulder muscles tighten up and do not relax. If the shoulder muscles are not loosened by deep tissue massage or acupressure, or a hot water shower, the pain felt on top of the shoulders will extend downward to the shoulder blades and to the side towards the upper arms. The pain is felt across the top of the shoulders and when it extends down to the shoulder blades, it is felt across the shoulders as well.