J.G.
I don't really have a solution for you but I can emphasize.
My father is terminally ill and will not be around too much longer.
He wasn't the best father growing up and then did something that really set my brother off as he was living with him in the past.
They got into a huge fight saying all kinds of nasty things to each other and I had to offer for my father to come move closer to me.
My brother and I don't live in the same state.
Anyway, here is my father not knowing how much longer he has to live and my brother won't forgive him.
Now on top of that he has even stopped talking to me or my sister because we are helping dad out!
I have tried to talk to him to let him know he is going to be gone someday soon and way down the road he is going to regret all of this.
My father has repeatedly emailed him and told him he was sorry and to please forgive him.
Nothing we do works so I do know family disputes stink and sometimes one is just stubborn and no matter what you say it won't matter.