What should i do ?!?!?

how are you supposed to be nice to someone that is not there? If he is too busy for you, then you should move on, never met my biological father and I have a real great dad! All you can do is be kind and understanding of the issue. but I can understand that it's hard to feel empathy for someone who is not there for you, and they need you now for support, but I think you should still say sorry about the upsetting news, but as far as caring much, I wouldn't in your shoes.