Hi there ~
I understand your concerns. I believe that the pain in your armpit is due to a problem with having lymphadenitis
. The cause may be anything between simple infection to cancers. If the nodes persists and you feel like the pain is not going away you might need to consult a doctor. I believe that the nodes are also impinging on your nerves causing you to have pain in the areas that you mention. I hope this helps clear your doubts. Please also consult a doctor who can performa physical examination and recommend the next steps, which might include a fine needle aspiration cytology (FNAC) or biopsy
of the nodules. I hope this helps.
Take care and have a lovely day!