Is it bad?

How can I tell my “best friend” I don’t want to be around or talk to her anymore? She literally knows every single detail of my life, the good and bad and I’m afraid she will post it all to social media because that’s the type of person she is. I’ve seen her do it to other people. I’ve wanted to leave this bad friendship for awhile but don’t know how to confront her or deal with her drama. She can be a very toxic friend and acts like a child and bossy. Some days I’m scared to even tell her what’s going on because she will be mad at me and I don’t want to deal with her silent treatment. She also gets pissed if i band out with other friends, she will legit be rude to me. I could go on and on. How to I confront her?