It’s a good question, perhaps some of the therapists here could share better tips.
But in my own humble opinion, time heals everything. All that anger, frustration, shame etc disappears over time. I used to hate my dad and had all the “what-ifs” in my head but over time, I’ve stopped hating him.
I never really healed from this but I guess I got busy with life and this just really wasn’t a priority anymore. He’s got his own (other) family now and whenever I see pictures, it still does bother me slightly. I just try to focus on other stuff that is probably more “worthy” of my energy and time.
Not trying to shrug you off here but I guess for you, it’s worthwhile reading more stories to see how other people manage situations like this. Maybe that’ll give you inspiration and hopefully some sense that you’re not alone too.
Some related stories: