No contact grieving process

We had an intense relationship, deep mutual love but two difficult traumatized people, our personal issues got in the way.
He didn’t want professional help for his own issues nor a relationship therapist. He did do his best on his own but had difficulty confronting himself. I couldn’t handle it anymore so gave him a deadline of getting help, which he couldn’t.
We concluded that it just doesn’t work for now and that I need to continue fixing my own issues, he has to do so to to get us back together but I don’t know if he’s going to get to that point. At least now I don’t push him anymore, I hope that will give him the space to find his inner motivator… We had something special.

Anyway I’m busy finding additional mental health care for myself. Takes a while and a shit ton of effort.

What do I do with the anger I still feel of how I’ve been treated, he was just mean sometimes to me (and I probably were as well). At the end he couldn’t say a honest sorry anymore and I didn’t dare to talk to him for weeks because of the destructive patterns we got stuck in.

But… How do I handle this anger? How do I release? How can I forgive?
I mean I let him go too far because I didn’t want to give up and didn’t dare to stand my ground because I was afraid of losing him so it’s partly my own fault so I tend to try to forgive myself for that and with that I also forgive him. But, I can only say this rationally to myself. Any tips on how to actually process this pain?