Hang in there, hon. I think you're grieving the inevitability, the finality, that you will never have the chance to resolve the past with him. That is a big thing, perhaps bigger than you realise.
While he lives, you feel that somewhere, there is always the chance that he will come to you and say, "I realise now what a terrible time I gave you; I'm sorry." Even if you knew that was most unlikely, while he lives it is still technically possible. But already it is out of reach and that little part of your brain clinging to hope, is now realising that and you begin to grieve. As you needed to years ago.
Relax, let it happen. You need tis. You need to forgive yourself and at some level you need to let go your hope and your need to hope that you had.
There is a meditation you can do, where you close your eyes and relax. let your mind roam back to a time when you as a child had a rough time. You as the adult, now mentally walk down the road to that child. Go to the child, wrap her in your arms and hug her. Tell her that you are keeping her safe from here on, she will never be hurt like that again, you won't allow it. Then take the child by the hands, turn round, and walk back to your life now.
You might need professional help with this, but it is something you need to do when you feel able.
This is normal for you to feel this way.
Marg