Hi welcome to Health care magic forum.
Thanks for calling H.C.M.Forum.
you have been sitting at the computer for the past two months, with the arm extended. Now you are getting extreme pain in the area where ribs meet the breast especially while riding the car, or when you touch there.
It appears to be the muscle stretch, or may be
cervical spondylosis, as it has happened after a
stress period of 2 months, i advise you to consult an orthopedic surgeon for diagnosis and treatment.
In the mean while you can apply some rubefecient locally for temporary pain relief.
I advise you to avoid potato, other tubers, tomato, egg, chicken, and sea foods to avoid more pain.
Wishing for a quick and complete recovery.
Best regards.