I’m feeling lonely

I had a falling out with someone I used to be friends with, because she set me up with one of her guy friends and me and him dated but he ended up cheating on me, and she had treated me differently ever since, basically acted like I didn’t exist. She knew about what happened, but she didn’t bother to comfort me or check up on me to see if I was okay. She confronted me about why I had gotten so distant and I told her about how I felt and she turned the whole thing around on me and blamed me and defended her guy friend for cheating on me. I was also supposed to be in her wedding. But the point of this is, is because ever since all of that happened, I’ve been really lonely, and all of that made me think if I’m a bad, toxic person who attracts drama or if I’m just bad at choosing friends. And whenever I’m lonely I think about how lonely I am and it leads me to remember all of that and I just feel awful. How do I stop? What do I do?