This was me for many years.

Quotes from: Lewis B. Smedes book, The Art of Forgiving —

"After we have been wronged-and wounded in the bargain-been swindled, cheated, abused, or demeaned, no human right seems more sacred than the right to get even with the scab who wronged us. We want to get back at him, make him feel-at the very least-as much pain as he made us feel. Nothing could be fairer. Or taste so sweet. Or seem more deserved. "They're gonna get it," we heard Richard Nixon grumble on his vengeful tapes. I think the ancient Greek poet Homer was smacking his lips when he drooled about revenge. It tastes so sweet, he said, we swirl it around on our tongues and let it drip like honey down our chins.
We want our enemy to suffer, yes, but we also want him to know that he is suffering only because of what he did to us. We don't want him to admit he made a mistake, flip an apology in our direction like a fifty-cent gratuity, and go on as if he had done nothing worse than burping before dessert. We want the satisfaction of watching him turn and burn with hellish leisure on the rotisserie of his remorse."

After the first year of extensive therapy, I no longer felt there was anything to forgive of those I used to insist wounded me: ex therapist, parents, ex H, etc. and, I was not interested in forgiving anyone when my therapist brought up the subject, and suggested I read Smedes books. I never did, she read the above portion to me. I went from wanting vengeance, and usually taking it out on myself, magically thinking it would affect them, to having healed memories. Now, I'm living my life free from those burdens. Never needed to head to New England, and blast my ex therapist, because of the pain I endured, because of a botched termination. I'm good — real good.

"Forgiving does not erase the bitter past. A healed memory is not a deleted memory. Instead, forgiving what we cannot forget creates a new way to remember. We change the memory of our past into a hope for our future.”
― Lewis B. Smedes

Smedes is a Christian author, but his books on forgiveness are more universal. My therapist is an atheist, and so was I at the time. I know she has given them to my Jewish friends to read, and theyfelt they have benefitted from them.

...but, you don't need to read books