hopeforsis,
Welcome to the site, you will find much love and support in learning to live YOUR life with your AS. I too have an AS who, to our knowledge, has been an alcoholic for 10+ years, but I think it has been going on closer to 25 years (basically we thought she was "the party girl"). You are correct; all your love for your sister along with their drinking will drive you crazy if you don't seek the help and support you need to live with this. Have you gone to an Al-Anon meeting yet? If not, I would recommend that, as well as this site and reading as much as you can to understand this disease.
There is always hope that the alcoholic in our life finds their bottom and seeks help to live their live without alcohol, but there is always the flip side as well. For those who seek recovery and learn to live their life day to day without alcohol, there are the others who choose the other path and slowly kill themselves. Whatever direction your sister takes, you will need support to learn how to live with this.
I've found that this site, along with Al-Anon and education helps me avoid the craziness that my sisters drinking has brought to my life. I'm basically re-living this experience, as our Dad was an alcoholic and died at the age of 46. The craziness of then has probably intensified even more with AS, since she is following the same pattern he did and she is only a few years away from the age he was when Dad died, was in intensive care back in February for 10 days where she came close to dying, is a severe diabetic, as well as having severe liver damage. If I didn't have Al-Anon, SoberRecovery, faith in a Higher Power, and detachment with love (at this point), I would be bouncing off the walls of the "Ha Ha Hotel" right now.
My thoughts and prayers are with you and your sister.