lumps and bruises???

I have a painful lump in my armpit. Is it just a lymph node or should I be concerned? Also I've been finding bruises on the front and back of my legs and have noticed I've lost a lot of hair. Two months ago I was extremely sick, at first I thought it was strep and then wondered if it was mono.... I tried several antibiotics and I took nearly a month and a half to get better. I was tested three times for strep and once for mono.... all turned up negative. I don't feel like I have completely recovered, I get tired easily and can't seem to get enough sleep.