Hi Pat, welcome to the board, you will find lots of helpful advice here, and people who you can really share your problems with. I'm so sorry to hear what you are going through at present. As others have said, you don't have to "shun" them, so go ahead either write to your Dad or if possible just turn up at the house to see him. If they are shunning you now it can't get any worse if they turn you away, but hopefully you will be able to see your dad.
Keep in touch