I am hesitant to post because I have recently joined and only recently stopped drinking, but I will share what my family (those who are now sober) have shared with me.
I asked a family member the same thing that you are asking and what she told me was that because I am an alcoholic, I believe people will be obsessed and focused on my drinking, because I would be obsessed and focused on wanting to drink. Most people will simply not care, and it is our own fixated nervous fears that are trying to convince us to give in, or that we are doing something wrong, etc.
I don't know if that will ring true for you.
You can always simply say "I have an allergy to alcohol." You may get a "huh? Since when?" "I react differently and very negatively to it than other people." I have been told to politely decline, "doctors orders".
Good luck
