Feel like I was gaslighted by my ex-best friend

I can’t seem to overcome high levels of resentment, confusion, anger and injustice over being “dumped” and ghosted by my ex-best friend about a year ago.

I listened to Brooke’s podcast on toxic people, and I really struggled with trying to accept that there is technically no such thing as toxic people. I feel like this is one of those concepts that I understand intellectually, but every time I even think of this ex-best friend all I want to do is list off evidence of how “toxic” she is — she crossed lines multiple times trying to do inappropriate things with a couple of my exes and once with a guy I was actually dating, she leeched money from everyone close to her (including me) to pay for shallow things, she was too good at playing the victim and could never seem to take responsibility for her own actions, she openly disliked every other female friend I tried to make to the point where I felt like I had to hang out with them in secret, and towards the end, it felt like she only showed up in our friendship when things were bad in her relationship.

I can’t help but look at all of the terrible things that I overlooked in our friendship towards the end, and feel so ashamed that I wasn’t the one to “dump” her years before. I made so many excuses, like; she had a harder childhood than me, her mom is a bad influence, we’ve been friends for too long to end it now, I’m the only close female friend she has so I have to stick around, she doesn’t have as much money as I do, she never meant to hurt me, etc…

I always really tried to be a good friend to her, and honestly convinced myself that it was noble of me to even stick around. I never would have crossed the lines that she crossed with me… I didn’t think I had to lay down boundaries for some of the things she did to me because it just seemed like common sense to me that you shouldn’t do those things to your best friend!

Towards the end, I knew on some level that we shouldn’t be friends anymore, but we had been so good in the past so I was hoping I could just drift away from her naturally when I moved out of state like I had always planned.

The fact that she is the one who “dumped” me when she acted so awfully is what really really messes with me though. Trying to find reason/rationality in it makes me feel like a absolute crazy person… like she was trying to gaslight me. It’s like we were living in different worlds. It felt so unjustified and out of the blue that I just cannot seem to wrap my head around it. I don’t want to care. I don’t want to waste even a second more of my thinking on her, but I could go on for ages about this and I can’t seem to let it go.

I’m really struggling with this consistently even though it’s been a year since I’ve talked to her.
Where can I even start to work on this?

Any advice would help!
Thank you for your time!