I felt like that once. Fucking horrible. I was lucky enough that something came my way and things improved. But I'm an atypical example.
You know what I find helps? To just... do things.
Like today, for example. I'm going for a swim in the local pool. No real reason, I just feel like doing something nice and active. Gets me around and doing something.
Because doing random things like that make you feel a little better. (There is actually a biological reason for this, doing exercise releases endorphins).
And if you feel better, you know what happens? You'll come across as being calmer, happier, more content. And people will enjoy talking to you a lot more when you're feeling like that. And you'll have a more enjoyable conversation with them. So you'll continue to feel good because of that. Postive feedback occurs.
You could say it's "breaking the existing cycle", but that sounds crap because it sounds difficult. It's so not.
Because I'm asking you to "break the cycle". I'm asking you to go for a walk. Or go swimming. Or anything.
Are there extra-curricular things you can join at your school? Why not just do something just for the fuck of it? You're not committing yourself by trying something new.
You'll have exposure to more people and come across better to them.
It sucks that you're in an all-male school though, I feel so bad for you.