I hate, hate, hate how our culture mis-attributed the concept of forgiveness. Traditionally, and religiously, forgiveness is something that a transgressor had to ASK for. There's this idea that anger is toxic, and you have to forgive everyone. This is something that has been twisted in the metaphysical, neo-Eastern tradition.

Anger (and other non-happy emotions) are here to help us

Anger and frustration lets us know that there is a problem, that we may need to take an action. It helps us set boundaries with those we might not set boundaries with. It replaces paralyzing fear with a feeling that incites us to action.

Then there is a point where our anger no longer serves us

And that point usually comes after we are no longer actively being harmed. And that harm has been acknowledged and validated by our community (best case) or, at minimum, by ourselves.

It is at that point that we can accept the things we cannot change and have the courage to change the things we can. And it is here, right here, that I think "forgiveness" was substituted for "acceptance" by our culture.

You need to accept what happened

Accept that this person is who they are and will not likely change. Let go of your expectations for them, for changing them, for the dream of what you believed could have been or should have been.

And maybe one day you'll want to forgive them, that is completely up to you and not a requirement for healing.

But forgiveness is not mandatory

But we need to, as a society, stop insisting that a result of healing (forgiveness) is the cause of healing. Because it isn't. And that it is required for happiness and enlightenment. Because it isn't. And that people who are angry and are not able to forgive are deficient. Because they aren't.

Only you know if you are at the point in your healing where holding on to your anger is helpful or hurtful. Only you know if this is toxic for you. But you won't be willing to let go of your anger as long as it meets your emotional needs for control, for safety, for boundary setting-mojo. The next step for you may be exploring how to do these things without being compelled by anger.

Basically, what I am saying is that you don't need to forgive and forget, you need to let go and move on.