Have Painful Bump On Upper Back And Swollen Glands. What Could Be It ?

Hi, I have a fast-growing, painful bump on my upper back. It started off painful and I can t even sleep on that side of my body. My neck feels soar, as well. Today, it was diagnosed as an infected sebaceous cyst . I seem to get them every couple of months on my upper body where there is practically no hair (shoulders, side, back). This time it occurred after very swollen glands and then a debilitating migraine and then the next day the cyst grew. I have been on antibiotics every couple of months for my throat which the doctor said was mono/strep. But I m almost 40 and in a relationship and can t imagine where that would come from. I haven t had the best health insurance lately and I think the docs are just treating the symptoms. Bottomline: I have these painful cysts and swollen glands every couple of months. What could be going on?