People can be really selfish in certain ways. If they feel blamed over something they can't change, and maybe even moreso when they feel guilt, they will go on defending themselves to the end, without any regard to your pain. My therapist had me send letters of forgiveness so I could unhook myself on my end. I'm not talking about the abusers themselves but others like your Dad that you want a relationship with. Maybe this would be a way to finally tell them. It didn't go perfect but at least I had an opportunity this way to have my say uninterrupted and finally get some closure on it.