The difficulty is telling anyone other than your absolute closest friends that you are an alcoholic. I have only just come to terms with this myself and I don't particularly want to broadcast it to all and sundry. Of course, if they don't understand the urgency or the absolute necessity that you protect your sobriety, they may feel able to try to cajole you into having a drink. I would like to think that if they knew, they would be understanding and supportive.
I have taken to telling people a diluted version of the truth, which is that alcohol causes me to become very anxious, so I'm just not doing it anymore. That seems to be working so far. I suppose I am fortunate that I am happy enough to be around people who are drinking without it making me want to drink. In fact, being around people and watching them become less and less articulate as they drink more and more makes me really happy that I am not going the same way.
Good luck with it all.