Just wanted to reach out. I've been there with the feelings you're experiencing right now. But that's just it .. It's right now... It doesn't mean it's forever.
Your May get D or you may not. Nobody knows that answer right now. Don't let his behavior dictate your actions and response. By all means continue on with the birthday party. It's a shame H will miss out on the birthday party but that's his choice, good for you for putting the invite out there.
Anyway, not much advice but just wanted to sympathize that. I know how you feel. It's a long bumpy road.