UPDATE: I [22 M] cannot seem to move past my father's [47 M] treatment of me when I was a child even though I really want to. Any suggestions for how to approach this?

I originally posted around September last year for advice (here's the original post), and I finally have an update if any of the people who posted advice to me are interested.
So last year after the post I (now 23 M) decided I didn't want to talk to my father (47 M). I was initially supposed to see him the following month, but opted not to. After asking a friend for some advice I decided not to talk to my father anymore. So for about a week I didn't, and it seemed to go fairly well. Then he rang one day (landline doesn't have caller ID) and completely threw me off. I was short with him, which he noticed and asked me if I was okay. I lied and said I was tired which he appeared to accept, although rather reluctantly.
About ten minutes after I hung up, he called my mother (48 F) on her phone. He asked if there was anything wrong with me, and she explained (with my permission) that I was upset because of how he treated me during my childhood. He understood, and was apologetic for it. She also told him that I didn't want to speak to him, and that I would contact him when I was comfortable to.
A few weeks later after no contact he rang me to apologise, and I ended up reestablishing contact with him. This continued for several months, and seemed to be going pretty well. Then he started having issues at home, and started being more distant - he'd make excuses to not have a long phone call, we'd go a few weeks to a month without any contact, that sort of thing. I realise this probably doesn't sound like much, but it was depressing not to talk to him for long periods of time.
Anyway, something happened which made me think "he's never going to change". He was apparently treating his girlfriend poorly, acting sullen around her and making her feel bad. This was how he used to treat me as a child, and I decided I was done. I didn't want someone like this in my life, and so I made the decision to go no-contact. I sent him an email explaining how he made me feel as a child, gave examples of things he'd done and told him I didn't want to talk to him again. It was not an easy thing to do, and part of me still wonders if I did the wrong thing. What doesn't help was his response - he was completely understanding and apologetic, and said he was still there for me if I changed my mind. I know this sounds odd, but if he'd sent me some sort of scathing reply it would have been a lot easier for me.
Anyway, there's the update. Sorry for how long it is.
TLDR: Went no-contact with my dad, he got back in touch, talked for several months until I decided to go no-contact again.


Source.