Thanks for asking at Healthcare Magic. I read your question and I understand your concern. Sharp pain in arm pit just after you woke up means it simply a muscle or ligamental sprain due to abnormal posture during sleeping. I would like to advise you to take pain killer like advil with two glasses of water. Do chinup and pulls up excersize and swing. Do regular aerobic excersize thirty minute a day five times a week. If problem still persists for doing the above for more than fifteen days then contact Orthopedic surgeon. Hope it helps best. Don t forget to rate this answer and close the discussion at Healthcare Magic. Take your best care. Regards Dr Ejaz