Essentially, humans are animals. The laws of the animal kingdom apply regardless of species or age. Those who gave off the confident, outgoing, boisterous personality were given preference because you're teachers must be of low intellect and incompetent. However, they are still animals, so their preferences turned into decisions which effected you. I've heard stuff about grants and money, that's possible as well. Most important is that they were jocks themselves.
To be honest, you seem a lot like me, but a bit more extroverted. I was quite close to doing what you did on some occasions, but I never could bring myself to hit anyone even though I went to an all boys school for 6 years. Maybe you just have more courage than I do, but I would hardly consider you to be violent for defending yourself. I'm violent as well, but it's in video games.
I'm 20 and I haven't had a girlfriend either, but a lot of it is withdrawal from what happened to me. You aren't alone is what I'm saying.