What Could Cause A Painful Lump On The Left Armpit Which Looks Like A Bruise?

I'm a 24 year old female, 200 lbs. A couple months ago I had a painful lump in my left armpit, which was also discolored basically like a normal bruise, it was kind of pink but also purple/blue like a bruise would be. At first I chalked it up to needing a new razor, I figured it was an ingrown hair. But after a couple days the pain was really severe, even when I was just sitting there not doing anything the pain would be pretty uncomforatble, and the lump was pretty big. I was going to make a dr. appointment, but after a few days the pain went away completely, and the swelling went down but the lump did not go away.



Last week I started feeling the same pain in the same armpit, only a couple inches closer to the top of my breast. To be honest, I wasn't sure if the discomfort was from a new bra I had purchased that had an underwire, which I'm not used to, because the pain went away more quickly than it had before, and the only other thing that happened was it seemed like it made my entire armpit kind of hard. Like, when I touch my right armpit it feels relatively firm, but squishy (I'm 200 lbs!), but when I touch my left armpit the whole thing feels denser. The actual lump is relatively small, but it is hard. If I had to guess, I'd say it's probably the size of a pea or a marble.



In addition, I'm not sure if this could be related or not, but I've been having dizzy spells, or vertigo I'm not entirely sure what the difference is. At first I experienced the dizziness before a meal, so I figured it was from being hungry (even though that's never happened before.. and I've had an eating disorder in the past, bulimia, so i figure my body's no stranger to being a little hungry!). But yesterday was the third instance of dizziness, and it occurred 15-20 minutes after I ate dinner, so there goes the hungry theory!



Can you help me?