It is absolutely worth going. You don't want look back with regret. Turn every rock before you come to the end. This is a big rock.
The email is probably a way for him to ensure you know what his intentions are. I'd thread carefully on this one. It wouldn't surprise me if he threatens not going this weekend if you resist cooperating. Keep your cool and your emotions in check.
It obviously is hurtful and bothersome. Collect your thoughts before responding. If you are replying by email....I'd suggest running it by the board if you are open to it.
My .02 cents.
Me:45 ExW:48 M:04/97 3 Bombs & 2 ReCons 1st BD 11/10 D Finalized 4/20 D-16 S-14 Going in one more round when you don't think you can. That's what makes all the difference in life.~Rocky Balboa