My first though was lymph as well. I often get sore armpits when I am down with a bad cold. But due to the risk of cancer, family history, and your age, I think a check for breast cancer if def needed! Every state has programs set up for those whose can't afford help. I know it is difficult to get info on them, and then to go through all the paperwork (I HATE it), call your local health services dept (if you are in the US), and tell them your story, see if they can help.
Is the sore still present along with the pain? My first thought was cysts or lymph tissue but the sore complicates things, along with your family history. I agree that you should be seen. Good luck! Also there are groups that help individuals pay for certain medical care, if you can't find any remember you're health is worth it.
Hi
Welcome to the MedHelp forum!
Cancer can hurt also. Having said that, they could be multiple boils. They could be persisting due to underlying diabetes or eczema. Also brrreast should be examined for a lump. Please go to the ER. Take care!