Thank you both (Likealion and GingerM) for sharing your stories; there is so much in both these posts that I recognise, it's scary.
I also look at my Mom now, and try to separate the person from the Alcohol - which some days is more difficult than others. Yesterday she was relatively dry, but completely lied to my face repeatedly as to whether she's drinking. She's never going to change - the only thing I can change is how I deal with it.