“Large lump in right armpit?”

I developed a marble-sized mass under my right armpit 2 weeks ago. The mass has now grown to almost golf ball size. It is hard and does not move and my armpit appears to be slight swelling. I take no medications and I do not smoke. I have fibromyalgia, DDD, ankylosing spondylitis, and Klinefelter's syndrome. I use cannabis and occasionally take ibuprofen when my inflammation gets out of control. I just got through 2 months of hip pain and now I am battling severe pain and weakness in my right arm and hand. I have no insurance, so I am playing the waiting game. I don't sleep well, have major depression, brain fog, severe exhaustion, being itchy all the time, and loss of appetite. My wife has stage 4 non-Hodgkin's Lymphoma and I am afraid of having cancer also because we have 6 kids.