Like others here I too have family members who cannot understand why I can never drink again, that all it takes is one drink and I'll end up binge drinking and getting drunk then its back to being ill for a week while I try and dry out.
My father is the worst, he and I have almost come to blows in the past and have had full blown arguments when I'd previously tried stopping drinking. His attitude is a man is not a man unless he drinks - he's actually said that (and worse) to me. But my father can stop at a couple of drinks and his view is that if he can do it then anyone can do it. In the end I just accepted he has his views and while I can't change him I can just accept that is the way he is. But I do sometimes still get annoyed when he asks if I'm still not drinking. Not because he's asking as such but because when he does he then starts talking about how one drink won't hurt me and I feel sometimes like I'm talking to a brick wall. He'll then try and get the rest of the conversation around to drinking. I guess he's just looking for a reaction from me, hence why we nearly came to blows once.
Thankfully everyone else in my family and even most of my friends have been, while I wouldn't say all of them have been totally supportive, most know that for the sake of my health I have to keep off alcohol. I just wish my father would get that message.