I think the best thing to start is just don't pick up a drink.
It doesn't sound like you have been drinking a lot on a regular basis (?)
As far as what to tell people and/or your wife...how about just, "No thanks," if they offer a drink. I mean, you don't have to share with anyone right now about why you aren't drinking. People don't really ask me why. Spend time on this site and read as much as you can. It will start to make sense to you.
At some point when you are feeling more stable you can talk about it with your wife, when you've decided what you want to say. For today, just don't drink. There's time to figure out who and how much you want to tell. I don't talk about it with people outside of this site. I don't use the word, "alcoholic," with people who are not in recovery.