You're not selfish. I'm really sorry for your loss and that you now have this going on.
I've been through a similar set of circumstances. I no longer have contact with my father. It was not an easy decision, and it hurt at first, but for me it was the right decision. He had an exceptionally long time to ever show any sign of caring for me, much less loving me, and did not care about losing me. Which confirmed to me it was the right decision.
Life is too short and too precious, and filled with enough pain and stress, without keeping toxic people involved in our lives when all they contribute is to cause pain, distress, and aggravation.
For contrast, when my grandfather lost his wife of a fair bit more than 45 years he took the time to make sure I was coping and to offer support to me, and to maintain contact and our relationship.
That's what people who love us do. They sure as hell don't use emotional blackmail to manipulate us when we're grieving. There is no excuse for that. None.
You're not in the wrong here, and I'm sorry you're going through this. I really am.