Are you not wanting to go to make a point at your Dad? To be honest, I think the point will be missed. I agree with Daffy, I think you should go and if you're not comfortable, you can leave.
I think that you should consider making a point of requesting you and your Dad sit down and work through your feelings (not at the party). Maybe he's thinking that you're not all that bothered about him and he doesn't attend your celebrattions because he thinks he's intruding, or he's not genuinely wanted there. If he doesn't change after that, then at least you tried.