Moral support?

Hey everyone. So this past week I've gotten into a really big fight with this girl on social media. She's been really immature and kind of dragged me down to her level and I said some things on social media that I wish I hadn't. Basically it got to the point where she brought up stuff from my past all over social media. Stuff I've already forgiven myself for. It's gotten me really down and her and another girl are spreading horrible lies about me. Does anybody else that's older have a story about mean girls whenever they were in high school? I would love to hear them. It would make me feel way better :)