Some good comments here, and I have come to agree with the strong ones made.
This is TOUGH - and I have been on both sides of it, so to speak.
As the child of an alcoholic mother, I "got in trouble" for talking to my best friend about my mom and our family life. I HAD to have someone to share and deeply resented (and was confused at the unfairness) of my parents having my Godparents, their best friends, to confide in etc. I still remember the hurt of all this.
As an adult, not yet in my own full fledged alcoholism, I tried to shift from that child's perspective and understand my parents way of dealing with my mom's illnesses (She is also bipolar).
As a raging alcoholic, I was angry and resentful at my mom in particular for sharing her devastation and abject terror, among other things, over my drinking. Especially when it was to a person I couldn't stand, who happens to be a good friend of hers (that's another story ALSO based in my resentment - there's a pattern here....).
As a recovering alcoholic, I can (now, at 2 yrs sober on 2/21) respect how we all needed support (and healing from our different types of alcoholism, as well as issues addressed in Al-Anon, for example) - we still do. My recovery isn't just something my parents have "Switched gears to" - just like my mom's wasn't that way for me.
I am also gaining wisdom and discernment in how my step-son is behaving towards his father, who is also in recovery.
It is complicated, challenging, and truly, IMO, calls for EVERYONE involved to act with love and compassion. The hurt will out, and it should - but for me, healing in all directions, is the goal.
Best to you in focusing on YOUR part of this family equation. You're lucky, like me, to have family who cares very much.