My Ex's new girlfriend requested to follow me on insta today

I was with my ex-boyfriend "Peter" for 13 years, through thick and thin. Around year 7, he cheated on me with "Anna." I tried to get past it, I really did. But I did ask him to cut contact with her. He promised and deleted everything. But then Facebook told me he was still in touch with her. I was so shocked and hurt.He cut contact again. A few weeks on Facebook recommended his new profile that had only her as a friend to me. We talked or rather fought about it - he promised to cut contact again. We did this dance two more times. I know. My only pathetic defence is that I just loved him so much back then and he swore he loved me too, and I'd grown up with the moral mantra that you didn't give up on "true love."

Fast forward to three years ago: Peter always had mental health problems and severe depression. After years and years of him absolutely refusing treatment, most of our friends and my family alienated and keeping their distance (because he found them annoying and would get upset, so I limited contacts to when he wasn't there, but he was always there), something just broke one day and I broke up with him. The last few years the relationship was incredibly difficult, empty of any emotional or physical closeness and unhappy (from my side, at least). We were just... roommates, barely even spoke to each other in the evenings. The only thing we did together was eat dinner, then he'd hole up in front of his computer.

He took it very badly. Got blind drunk over weeks, threatened suicide, self harmed, tried to monitor my phone and stuff (tried installing spyware). He just wouldn't let up. Told me he had been planning to propose to me. I moved out secretly one day and just left a letter. He trashed my reputation with remaining friends for this.

His new girlfriend requested to follow me on insta today.

It's Anna.

Her insta isn't set to private, and of course, I looked. They've been together for a year, and she has a gazillion pictures of them looking happy. She made a post a few days back of how "life" tore them apart, but "destiny" brought them back together. He refused to take pictures back when we were together. And now they live his happy life with quite a few of our former friends, and I'm left with my hurt.

I know I'm better off. I'm so much happier. My life is so much easier now. I love coming home, not walking on eggshells anymore, etc.

But I struggle with resentment, and today, I am feeling utterly humiliated that Peter and Anna are now a thing. I can't help but hate him so much for this. If this is who he wanted, why, why, WHY didn't he just break up with me back then?? I tried so hard and I gave everything. I suffered so much because the two of them back then (I know I should've left).

I'm also still hurt over how people I considered friends.. just.. dropped me.. like I was nothing.

I feel SO humiliated.

And so stupid, annoyed for letting this get to me.

I'd love some perspectives on this, please. I'm a bit lost.

Quick edit: Thank you for all the replies!! <3 You all really helped in putting things into perspective for me, and while some feedback was uncomfortable, it's good to have heard it.

I need to do some reflecting and thinking. I'm going to check if my old therapist is still around and if yes, ask if she has capacity for an hour.

And, yeah, I did block her account. I'm not scared of confrontation, but nothing good would come of this, and frankly.. this woman was my nightmare person for so long, I just want to be rid of her (and him in extension) and will happily never see her face again. And I'm not a fan of drama.

But considering the shock and old feelings it triggered when I saw her face - I have some thinking and reflecting to do.

Lots of love to all of you! Thank you again!