Ingrown hair or STD ?

I'm 16 and I made the mistake of losing my virginity just this school year, the girl I did 'it' with had already slept with a guy back in her hometown, and with a friend(which I didn't know at the time)

To the topic..I recently had a huge spree of masturbating many times a day for a week or so, I'm not sure what caused it but when I was done I had a reddened sore on one side of my penis, a few days later, a large bump had grown about halfway up it, and just today, I popped it and a yellow-white cream thing came out, it was kind of liquid, but not exactly fluid. There is a hair growing through the bump, so I'm not sure if it's a ingrown hair or anything, but it hurt to touch it when it was ready to pop, and when I try to pull the hair it hurts as well.

So really, I need some help, is it a ingrown hair? a STD from my mistake? Or just a zit because my shower schedule isn't exactly perfect?

Hope you guys can help..