I'm not going to attend my fathers funeral because I never had a relationship with him
Who were you raised by?
I was raised by my grandmother since I was 6 years old.
Since you didn't have a relationship with your father then you shouldn't be expected to go to his funeral. You should go to funerals for people you were close to.
Exactly, he was never a real father to me.
I'm so sorry to hear that. Your feelings are involved in it I see. Its better to just try your best to forget it all.