I have studied your case.
It can be rotator cuff injury
which may need MRI for confirmation.
Medication like methylcobalamine with muscle relaxant
will reduce pain, you can take them consulting your treating doctor.
You may consult physiotherapist for further guidance. He may start TENS
which is helpful in your case.
You may need to take rest for early healing.
Also check your vit B12 and vit D3 in your blood.
Hope this answers your query. If you have additional questions or follow up queries then please do not hesitate in writing to us. I will be happy to answer your queries.
Wishing you good health.