Oh, and, as for your dad, I'm so sorry. It's one thing to have H have an impact on you, it's another to watch the people who love you hurt, too.
I wrote an email to break the news to my dad and his GF. My dad had been so thrilled that I'd found a good man to love me and take care of me. When he found out, he was on the highway driving (GF had called him and told him about the email). He told me he had to pull off the highway because he was sobbing so hard.
I've never seen my dad cry. That really helped me understand that other people saw how much I didn't deserve H's choices. I was still in survival mode at that time, so it also helped me understand how much I had to mourn.
This is a loss for your dad, too. He thought he had someone reliable to take care of his beloved daughter, and instead that person hurt you and is leaving you in a bad situation. He probably also hurts for the broken home his grandsons will have now. H has broken your dad's trust in him as well.
H has done many things that hurt a lot of people and it's time for him to face the music. You're not shielding him from the wreckage he's caused to multiple people.
