Khendal......I suggest that you look into AdultChildren of Alcoholics.....and consider attending meetings to get support for yourself (and perhaps your sister, also)......In addition to your ususal AA meetings, of course.....
It would mean so much for you to be fact to face with others who have h ad similar experiences as yourself......
I also underline Lexie's advice to you........
I hope that you continue to read, here, and stay around for the support that you can get from others....
I commend you for coming for support...you are fortunate that you can work through these problems at your age...rather that waiting years and decades, like so many others........
dandylion