I haven't spoken to my dad in 3 years
Why would you avoid speaking to him for 3 whole years?
Because I'm mad at him for the things he has done to me.
It sounds like it's been some time since whatever he did to upset you.  Perhaps you should consider letting go of the past?  You don't know how much longer your dad might be around, and you may regret not having a better relationship with him.
So what? He's a dick so whatever happens to him doesn't matter.
What he did must've been awful. I guess I can't judge until I know what he did to you.