Unfortunately, the principal is a bit like the HR departments that you'll come across later in life. They're there to protect the institution from you, not to protect you from anything.

I can't condone your actions because resorting to violence is generally not the best solution. I'm not going to condemn them either. Your teacher should have been paying enough attention to the class to notice you telling the other student to stop the first time and intervene at that point.

As for your parents, emotions are high in the immediate aftermath of something like this. If they are the kind of people who are willing to listen when they're calmer, talk to them over the weekend and explain what happened as calmly as you can. Explain that the teacher didn't notice and intervene when you asked the other student to stop initially.

That all said, you stood up for yourself and made it clear you're not an easy target for their BS. Hopefully, because of that, they'll leave you alone in the future.