I'm being harassed at school. I have all the facts about it and I got all the technical terms down but as I walked up to the principal I got cold feet and said I forgot what I was going to say. Why did I do that? I don't know ,but how do I get over it?

You MUST bring this up with the principle as they have ways of dealing with situations like this. I assume this is concerning another student.
You can only consider legal action once ALL available avenues have been exhausted..

I'm being harrased at school. I have all the facts about it and I got all the technical terms down but as I walked up to the principal I got cold feet and said I forgot what I was going to say. Why did I do that? I don't know ,but how do I get over it?

Put it down in writing. Explain that you have a problem that should be brought to his or her attention, but due to the sensititiity of the issue you would rather put it in writing. Then and present that writing to the principal.

Removed double post

I would talk to the principal with my parents, paper (as suggested by AK) in hand.

I don't think this is a legal question at this point.

First of course this may be more a bully situation, since we don't know. Harassment normally will be about race, or religion or a protected class.

But first your parents should be going to the principle after you explain to them what is happening. But a letter to the principal as to what is happening and that you need to meet with him with your parents.