What Causes Pain In The Upper Arm Which Radiates To Shoulder?

I get a pain in the right upper arm and is radiating to the shoulder and collar bone. The pain gets very severe in the nights and has been distrubing my sleep. X-ray of the shoulder AP lateral says that the "gleno humeral joint appears normal. No rotator cuff calcification is seen. No fracture is seen". I was prescribed Rabiplus capsule and Microsid capsule but there is just no relief in the pain. The slightest pressure on the arm results in pain. Activities like wearing clothes and putting the seat belt are very painful.

The orthopaedic doctors have not been able to diagnose. I am not sure but could this be a case of frozen shoulder?

What is the porblem and what remedy do you suggest?