What is the origin of these kinds of thoughts?

I feel repulsed by the other students, in my cl, it's partly their physical appearance, but also their mannerisms and behaviour, even the way they dress. My emotional reaction is such, that I am almost sickened to the stomach, by them, and find it hard to think about going to the cl. How should I approach this? The cl itself is really interesting, and fulfilling. Even the smell of a guy eating bubble gum makes me nauseous. Where does this sort of feeling come from? Is it normal?