I have studied your case with diligence.
As there was collar bone fracture
and now callus
formation ,there can be altered anatomy leading to compression of nerve in cervical region . shoulder exercises to remove compression of nerve is important part of treatment.
You can find good relief with physiotherapy
,tens and assisted exercises.
Neurotropic medicines like methylcobalamine will help you.
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.