Here is my thinking around "tell the family:" With all the enmeshed stuff in your family, I think you need to assert independence and autonomy from your family. I've followed along, and I realize you have a difficult and complicated relationship with them - but it doesn't sound like you've ever successfully broken the bond of parent/child.
Especially in the case of a difficult parent such as your mother it is necessary to verbally and emotionally separate - I know because it was the only way I was able to heal my life. I had to take my power back from my family. The interesting thing is that once that was done I was able to take my power back from all relationships. I stopped giving a damn about what my mother and others said to me, because I understood on a basic level that no one would ever fully understand me and as long as I made healthy choices for ME, it didn't matter what anyone else said. I certainly could not affect what they thought of me, and I stopped trying to be everything to everyone. They're gonna be who they're gonna be.
It is really freeing to step away from that type of relationship dynamic where I cower or worry or give in or hide/lie/cover-up, argue, mind-read. Honesty is the way to go for me. If I'm not hurting myself or others I don't give one hoot about what other people think about the nuances of my life.
Full disclaimer - I don't talk about my sobriety or my past drinking with new people I meet AT ALL unless I can trust them to be non-judgemental, so I get why you would have that fear with your parents/mother. But I did tell my mother about my abstinence. It seems like you consider your family as a reason to drink. Take away the opportunity to drink around them and you'll find ways to not drink around them. And yeah, my mother made snippy "comments," and I was able to see them as just another story line in her twisted convoluted story of, "How stuff is."Just because my mother (and my other family members) say something, doesn't make it true. I know myself and my truths. That's all that matters. She kept offering me alcohol every time I saw her for ten years after I quit, and I kept telling her, "I don't drink anymore." She was so much in her own head she couldn't even remember that.