From that I would say you've been bullied in some form.

I was bullied from the age of 10-16 and at 14 I started thinking like you but without the anger and viciousness.

Why do people bully? Because they want to make themselves feel better. Because they want to drag others down. Because it's what they've known all their life. Because it makes them popular, people are scared of them so go along with them etc. etc.

There's no anger in what I've just said but I am saying it from experience.