I hate my friends (coworkers)

Hi, I don't know how to start this, I'm just doing it to vent. Well, when I was in seventh grade, I had a classmate who didn't speak very well, I mean, she couldn't say anything without stumbling. Well, one day my friends and I asked her if she had had sex, and she told us that she had. Then she told us how it happened because we were very curious. The next day I didn't go to class, but my friends told me that the girl had told the teacher she regretted saying that to us, and then the teacher got angry with us for asking. After that day, my friends turned against the girl. They insulted her behind her back, calling her fat, ugly, and many other things. They also made fun of the way she spoke. I joined in the teasing too, but of course I felt bad and I regret it. Anyway, my friends created a group where they added 3 more boys and they all made fun of the other girl in that group. I was in that group too, but I never talked about it.But to make my friends hate her even more, the girl went to the teacher saying that we had fake Instagram accounts where we talked to boys, and it was true. My friends hated her for being a gossip, and that's how the bullying started. Every day we made fun of her behind her back. I was tired of all this because even my own friends started making fun of me. It wasn't as bad as insults, but they were always trying to make me feel bad and humiliate me. She was very angry, so one day I showed her the screenshots from the group chat where they were talking badly about the girl. The next day the teacher called my friends' parents and told them what they had done, and my friends seemed very sorry. After that day I thought they were going to stop everything, but I was wrong. I never told my teacher that I also participated in the incident because I was afraid, so I left it at that. After that day the insults continued, obviously more discreetly, and I made fun of them too; after all, they were my friends, right?

I'm currently in 9th grade. The girl changed schools and now my "friends" humiliate me and are always trying to ridicule me by taking pictures of me without my consent and uploading them to Instagram.And if I tell my father anything, they'll say I'm a gossip, and they won't be my friends anymore because they're the only friends I have at school. I don't want to be alone.

(Sorry if my original language isn't English)