My cousin outed me..😔

So I have a girlfriend, we’re long distance but we’re still doing good. Anyway, a couple months ago, I was talking to my cousin about me being bi and having a girlfriend and she started telling me I was being stupid and blah blah and I’m too young to know what my sexuality is. Then she threatened to tell my mom and I asked her not to. A few days later I came home from school and I found out she told my mom. My mom got SUPER mad (cause she doesn’t like the idea of me being bi) and she started shouting and screaming st me and saying I was disgusting. I then blocked my cousin and I’m still mad at her. I can’t believe she outed me.