Thanks for posting your query.
With the available described symptoms, there appears to be possibility of impairment of blood supply and nervous system of right upper limb.
This could be due to compression of described structure in neck by abnormal muscle or ribs (unusual presence of accessory 1st rib.)
You should consult with internal medicine specialist/ cardio-thoracic surgeon and should go for thorough check up.
You should also go for chest x ray
including lower neck.
Exact diagnosis can be made only after clinical examination.
Dr. Mayank Bhargava