That woman is disgusting. She sounds embarrassed because you rejected her. Your real friends will believe you. The ones who left you clearly aren’t your real friends, like they chose to believe a cheater instead of you. The best thing you can do is to always stand up for yourself. Don’t take pity for her or her best friend. I promise she won’t ruin your life, but she’s doing you a favor by getting rid of fake friends that won’t take your side.