What? Who exactly was making all those comments? Fellow students? Administration?

Introversion is a normal way of reacting to the world. Introversion is not the same thing as shyness, but it is a personality factor which means the person is more energized, if you will, by spending some time alone, rather than with people. Extroverts are recharged by being with people, on the other hand. You might find Carl Jung's writings on the subject. I believe he was the one who came up with these terms.

Is there a counselor or someone else at your school you can talk to? I can understand your anger, but getting too enraged is not healthy. I am glad you have control. But I think you do need to tell someone in your environment about what is going on.