Each and every poster has voiced my own thoughts on your situation. They are like those toddlers that are teething and are mean and hateful because they are miserable. Think about it, when you set the boundaries for children, in a fit of temper they say I hate you, I don't love you, they tell you they are leaving/running away and never coming back. It's the script. I know it hurts, but we all have heard it. Let him go off and stew a bit.

Things will eventually get a little better between your child and him, but it's definitely going to be a while. While waiting on him to simmer down, plan things w/your child.

I'm very sorry he's being a bit of an @ss right now.

Sit quietly, the answers will reveal themselves when you least expect them to.
The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.