First, I'm sorry to hear that your situation seems to have degraded. As long as you have hope and are willing to hang in there then there is still a chance. You don't know what is truly in his heart. He may be hurting and this is how he thinks that he can fix it. He may also not be honest with himself about how he is really feeling. I don't think that you should give up yet, but real detachment will really help you. He seems to get curious about you when you are out getting a life (like what he said about New Years Eve). Keep doing what is working.
I don't think sending the email was the greatest idea that you've had yet, but what's done is done. Don't be too upset if you don't hear anything from him. Also, I would plan on staying at the party all night. Even if he calls. Don't make yourself seem desperate. This isn't the end. My wife's parents divorced for two years and now have been back together for over twenty. It sounds like he needs his space so don't pressure him.
I wouldn't send another email retracting the earlier one. Ingrid is right about being with you out of guilt though. If you really thought about it, I doubt that's what you would want.
Good luck and hang in there, B
Me: 29 W: 28 T: 10 M: 7 No kids 2 Dogs and 1 Cat With Parents: 09/16/07 Apartment: 10/13/07 Back Home: ~2/16/2008