You need an MRI of the shoulder to see if you have a rotator cuff tear or perhaps a tear of the glenoid labrum--the cartilage that forms part of the socket section of the shoulder joint. Depending on the results you will either need to see a physiatrist--a physical medicine specialist--for definitive therapy or you may need to see an orthopedic surgeon.
I didn't have my ribs x-rayed, so can't rule out fractures there. That is where it hurts, especially to sneeze. My should blade at the back is sore, and seems to me to protrude outward. It doesn't add up for me. What is a labral injury?
I can't understand your reasoning. When I try to move my arm, the pain is not in my shoulder, but about 2 inches below the shoulder, at the back (shoulder blade area, and down my arm towards the elbow. The shoulder is not sore!