Cyst Under My Armpit..but I'm Worried About Staph Inf.

Hi I'm new to the forum...I'm Carlos.

This morning I was in my design class and noticed my armpit was kinda burning. I actually first felt the burn when I applied anti-persperant to it (Brand I use is Mitchum) this morning. I ignored it all day, until finally I was reaching back to grab a cigarette from my bag and noticed that my armpit felt as if someone had a lighter to it. I went into the library and into the restroom and lifted my shirt. Bam! There it is. The cyst (or whatever it is) is about the size of a marble. Thing is that I noticed that its tip looked like a zit or something similar, so I decided to squeeze it and pretty much nothing happened (though I noticed just a tiny bit of some liquid substance coming out). It is burning right now and cannot even touch around the area. Here what concerns me even more...

A while back I had that stuff that many men get around the genital areas (on the legs). They are small little bumps that appear and disappear, usually itching non-stop when you sweat or when it is scorching hot outside. My doctor then gave me a tube of some cream to rub down there and in weeks it was all gone. Then even more interesting, I realized that they started to come back, except in a more slower fashion and now around my legs, especially under the fold of my legs and on my arms.

I've started to realize that when I am dj'ing in a club, studying in the library at the university, or more recently, opening up my computer and messing with it, in a matter of minutes I get these bumps on my arms or behind my legs. The itching is unreal. As I scratch and scratch, they keep growing and growing, turning red. Even my friend whom I was tutoring for a physics exam noticed I was scratching and scratching, then asked me what was wrong with me. I said I had no clue, and that is when the word "Staph Infection" came out of his mouth.

I've noticed something parallel about both the genital thing a while back, and what's happening now, and that is when I am exposed to a dusty area, hot or humid atmosphere, or if I am somewhere where there are alot of people, I start to develop these bumps. I've noticed them on my stomach area (from which I now have a rash on and have had it for months), behind my legs, in the crease of my arm, and most recently, if I wear a belt with a metal buckle, that too will cause an eruption of bumps.

My brother had this a long time ago, but after being given the same stuff I was given, he never got it again. Also, I haven't read up as much info on Staph, but my friend who is a comedian and is funny most of the time, didn't look like he was joking around when he mentioned Staph Infection. I feel that for the past few years my immune system sucks and something is wrong. I've been meaning to go to the doctor and get this checked out again, but stupid me I registered for 21 hours this semester and don't even have time to eat anymore, literally. Other than getting off my butt and going to the doctor, what do you guys think about all this? Are dusty places a factor in any of this? Does the burning cyst that I have consist of anything associated with the lymph nodes being infected? Most importantly, am I a victim of the common Staph Infection?

Any comments or notes will help.