Hi ! From your history this looks to be repeated injury
syndrome- this means the muscles connected to your right shoulder blade ( scapula
) get repeated small injury at the same spot every time you are working with your computer. This may be due to faulty poster, the height at which your keypad and mouse is kept is not suitable. This is why you start getting after noon. So please adjust the height at which keypad and mouse is kept or may be the height of your chair needs adjustment most suitable for you. Taking Ibuprofen
400 mg three times a day (after food ) for 5 days, applying muscle relaxing liniments, rest and the adjustments as advised will definitely help solving your problem. You may visit Orthopedic Surgeon if necessary.