The commonest cause of shoulder pain in your age is neck and shoulder muscles strain, it happens due wrong working posture. Do hot fomentation and consult with a good physiotherapist nearby , if required have some sessions and learn some stretching and strengthening exercises. Understand the good working posture.
Shoulder pain can be localised to Trapezitis or may be radiating from neck
Do consult an Orthopaedic surgeon Clinical
Examination will diagnose cause or source of pain
Till then you can do hot fomenting of affected part
Also sleep adequately
I can understand your concern.
you have not mentioned if you had any injury?
if its due to an injury, then you should get it checked out by a orthopedician in person. if not, then you can take a tab. zerodol-th8 once or twice a day after food.
consult a orthopedician in person for further evaluation and management.
Dr. Anil kumar jain.
You have mentioned Right shoulder muscle pain without anything else i.e. neck pain / or stiffness / or prior injury to shoulder. that is quite rare. but with that much information.
(1) any infection might have caused that
(2) any local topical agent (such as body lotion etc.. might be causing local irritation )
(3) Bad Posture could one of the reason (using Devices at work, using Personal Laptops, and cellular devices.)
You also said about taking medicines to related to muscle sprain (no such specific medicine available, u might have got confused with muscle spasms. ) which probably could be either - muscle relaxant / pain killer.
No result in the swelling / pain ]with those medicines means the problem is not related with anything related with the muscles.
it could be either (a) Continuously using a bad posture in handling objets.
(b) some infection.
I advise you to consult a general physician and get blood tests one to clear that if it is infection.
if infection is ruled out then you may visit an consult an Occupational Therapist / work-space ergonomist / physical therapist who will be able to help you with Posture management and work related postures.
Rule out and come to a conclusion what exactly the problem is and consult appropriately.
Since it is over a week, consider it as priority and don't delay the matter further. STAY HEALTHY