dealing with the past (anger, regret and shame about past relationship)

I’m having recurring thoughts about a situation that happened to me 2 years ago. I thought I had moved past it, but it’s clear to me that I haven’t. I randomly think back on it and start arguing with myself about it from time to time. I’d appreciate any help on the issue!

Two years ago in the summer 2019, I met a girl and started dating her. From the start I told her that I had very little experience in relationships (I was 29 y/o at the time and she was 37), and that I was insecure about that. After a few weeks of getting to know each other, “problems” started.

I would say or do something that might unintentionally hurt or offend her, and I would apologize sincerely, but she wouldn’t let it go. Every time that happened she would mention all the past ‘missteps’ over and over again. If I tried to set some boundaries, or ask that she respected some of my wishes, she would say that I needed to learn to compromise. At first I thought I just wasn’t communicating well (and I probably was!). But as I started growing anxious and uneasy, every time I tried to explain to her how I was feeling, she would bring back the conversation to her and how I kept hurting her (and demanding apologies again). She would accuse me of being cold and selfish. She would ask me to dress a certain way to please her. She would tell me over and over again how I was the only girl she dated who was decent, all of her exes had been terrible people who treated her horribly.

I started seriously questioning myself (“I am really that selfish, that immature, that unwilling to compromise?”). But at some point I started feeling fed up and angry, too. We started arguing, yelling even (I’ve actually always been averse to conflict, I tend to bottle my emotions, repress my anger, say yes to anything rather than risk bothering someone else. I think I’ve only ever raised my voice and argued at two people in my entire life, and that girl was one of those two).

It lasted 3 months. One day, after a very tense week-end, I called her on the phone and told her it was best not to continue. To my surprise, she agreed, we had a calm conversation and ended it. I had a suspicion though, that it wasn’t over, that she would still try to contact me. The very next morning she proved me right with a text message. It was a generic “i hope we can stay friends” kind of message, but it made me think that it was going to start again, that she would still ask me to be her emotional support and blame me if I failed. It scared me, and I was really tired of arguing, so I blocked her without responding, without explanation. She tried to contact me by other means but I kept blocking and not responding. After a few months I received a last email where she reiterated the same accusations (I was selfish, I refused to compromise, I had hurt her, a friend of hers had died and she had needed me but I wasn’t there, etc.).

And that was the last time I heard of her. In the following months I had a lot of anger, toward her and myself, I had to work on that. Looking back at it now, I think it’s likely she might have been a malignant narcissist. I’m not mad at her anymore, and I’m not blaming her for my current feelings, but I’m still kind of mad at myself for the way I handled the situation. I can’t help but think “I should’ve confronted her”, “I should’ve been stronger”, “I should’ve told her why I blocked her” “I took the coward’s way out”, etc. and I guess, I still feel the need to justify myself.

I thought I had put that behind me. Maybe it’s because it’s summer and it’s kind of the anniversary, I’m starting to think about it again (same thing happened last year too). And since I’ve joined SCS since then, I started doing some models on it:

C I blocked that girl without telling her why
T I was a coward then, I still am
F ashamed, full of regret
A I try to justify myself in my head. I look up things on narcissism to support my theory (and seek external validation that I did nothing wrong)
R (??) I don’t take responsibility for my actions (immaturity / lack of courage)

C (the same)
T I learned nothing about standing up for myself (I want to do better next time)
F afraid, uneasy
A I keep rewriting some of my memories where I acted differently (I snapped back instead of apologizing, stood my ground instead of letting her have her way, etc.)
R (??) I don’t learn to stand up for myself

I tried creating some intentional models with different thoughts: “actually it only lasted three months, and you pushed back, some people go years without resisting.”

But I don’t know where to go from there. I keep thinking it over but there’s nothing I can do about the past. I don’t have a way to contact her anymore and anyway I don’t even think trying to explain myself to her one last time would be a good idea (if she really is a narcissist, definitively not).

In what ways should I coach myself to get past this? Thanks in advance for your help!