it may b the case of frozen shoulder
Imay advice u to take treatment of Acupressure and magmetotherapy from a specialist.
However, my advice;---
1. Place south pole of strong magnet to paining shoulder.
2. Place North pole of low power magnet on wrist.
keep this positio for half an hour twice a day for ten days.
3., drink magnetic water 4 time regularly.
Feel free to contact.