@PJ54 I hear your pain in your post. I wish I had some "miracle" advice for you. I don't know you or what you've been through or what you may have already tried. I can tell you some things that have helped me.
Forgiveness is necessary and forgiveness is not a feeling. There are Scriptures that tell us to forgive if we want to be forgiven. Forgiveness is a choice. And think of it spelled like this "fore-give". Meaning to forgive before, before they apologize, before they change, and most importantly, before we feel like it. The choice to forgive isn't for the person who did you wrong, it's for you. And you don't have to tell the offender that he/she is forgiven unless they have said they're sorry. You just need to tell it to Jehovah. The feelings of anger and resentment don't go away instantly, unfortunately. And the only way we can "forgive and forget" is if the offender is truly sorry. As someone else already said, you can forgive and yet not be friends with the person.
Don't be fooled by feelings of anger and resentment when they flare up. You'll be tempted to think that nothing has changed, that you didn't truly forgive. But that's a lie straight from Satan. The moment that you choose to forgive, it's done, regardless of what you feel.
Once you understand this, then you have to choose to change your attitudes and your thoughts.
Ultimate freedom is the ability to choose our attitudes. Others may have had something to do with how we got to where we are but we can now take responsibility for our attitudes and direction in life. The root word in responsibility is "response".
We can't control the things that others do or have done to us but we can control how we respond.
God is concerned about the inner person of the heart, our inner life. That is: what we think about. The way we think determines how we live and who we are. So we have to think about what we're thinking about. When those resentment and anger thoughts flare up and they will, stop. Say to yourself No! That's over and done. Then turn your thoughts to something positive. Think about all the things that we have to be thankful for. Offer Jehovah a brief prayer of thanks for something, anything. It's really hard to be grateful and resentful/angry at the same time.
If you haven't already, really pour out your heart to Jehovah. Really get specific about your pain, anger, fear, or whatever your deepest feelings are. Then forgive. Take whatever/whoever off your hook and put them on Jehovah's hook. Let him be their judge, let him be your vindicator. Then ask Him to be your healer, tell him you don't want to be angry and resentful anymore. You'll still have to do your part. Work on controlling your thoughts. It takes time. And some things are really hard. But don't give up. Keep praying about it.
"The righteous one may fall seven times, and he will certainly get up" Prov. 24:16
I'm praying for your peace.