First, why are you weaning off your antidepressant? Are you SURE you should be doing that? It sounds to me like you still have some depression issues. I know that this was an isolated instance, but I'd be careful about the depression. You may still need your antidepressant.
I understand how you feel. This was your anniversary, and you don't get to go out very often.

You were excited about going out without the kids, even tho it was a spur of the moment "date" -- it sounded wonderful, and you couldn't wait! I can almost FEEL the excitement!
Then lo and behold, AA butts in and he has to 12 step someone. Well, it IS important, and being a recovering alcoholic myself, you really can't say no.

You'd have to have a pretty darn good excuse, like a broken leg. LOL Your conscience just won't LET you say no. If you're really into the program, AA has to come first in order to stay sober. Maybe it's hard for you to understand right now, but these 12 step trips aren't just for the guy who's going into rehab, but they're for the person who's helping him too! It keeps us sober! I've been on alot of 12 step calls, and they did ME more good than it did the person I went to see!
I know that your hubby is going to take you out for your anniversary when he gets back. No, it won't be the same because it won't be your anniversary. But you can "pretend" that it is.

He'd BETTER take you out!!! LOL Now you have something to look forward to.

I wish you the very best, my friend. God bless and PLEASE take care of yourself! I know this is hard on wives & families. Best of luck. Hugs, Lee