Regarding you mum, you find wish to read this headline mainstream media story from only a fortnight ago: http://www.independent.co.uk/life-style/health-and-families/health-news/alcohol-cancer-seven-types-study-finds-7148321.html
For every problem there is a solution. AA for your parents, and have you ever tried Al-Anon for yourself? There is usually at least one group in every larger town. There are even online support meetings now. I speak from experience, it is good to talk.
Your article is perhaps a first step in that direction, to help yourself regain your own identity and life. I don't know of course, but your story sounds like a cry for help, for some anonymous feedback.
Alcoholism IS a documented medical illness, on every level: physical, mental, emotional, spiritual. Your parents were very very ill, not bad, people. That can be hard to accept. The not talking about it the next day, acting as if every thing was normal, very likely 'blackouts' where they really didn't remember a thing for the previous night.
I hope you find some Peace for yourself, and forgiveness for your parents too.