maybe it is still because my mother told me I was never allowed to talk about it all, as they are all allowed privacy
That's pretty typical of alcoholics. They need everyone to keep their secret, because any time it becomes public knowledge their addiction is threatened.
trom is right -- you don't have to say a thing in an Al-Anon meeting. The only thing expected of you is, when everyone goes around and introduces themselves, you say "Hi, I'm Vixen" -- that's all. You should feel absolutely free to NOT share in the meeting if you don't feel comfortable.