Was it right of me to kick this guy in the nuts?

Well, at my school, there is this boy, and he is always being a ist jerk. He keeps putting girls down, and talks about how weak they are and powerless. And I mean, ALL THE TIME and I'm sick of it. So, the other day at school, I saw him teasing this girl about how weak she was, and that she should be staying at home helping her family wash clothes. I interrupted the argument by saying, "HEY! Listen, I'm sorry that you feel this way about women, but why do you always tease us like this?" He then said, "SHUT IT YOU PUNY GIRL. I can beat you down anytime!!!!" And I said "Hey! I will too if you keep being a jerk!" He said "TRY IT! GO AHEAD! TRY IT!" His friends were giggling at the thought of me taking down a boy, and I took action without thinking and kicked the guy square in his nuts. His laughing was immediately cut off by his moans and groans and yells. He was cupping his crotch and rolling around everywhere and said he couldn't breath. I left but my friends said he couldn't get up for 10 minutes. I was wearing heels, and I do have a really strong kick (soccer player). Sigh. Now I'm trying to avoid this guy everywhere I go because I don't want him to see me, cuz I would feel guilty. My friends said tho, that he hasn't bothered them since, and that I got rid of his stupid istness. But I do feel kinda bad. I took action before thinking. Was this right of me?