Morning to all - hope that those who were out dancing the night away (aka JWN) have nothing worse than sore feet to deal with this morning 
Hi to nomore and gingerwig, nice to see you again ginger, and welcome back on the bus. I have spent so many years doing what you are doing - trying and slipping, trying and slipping - there is no shame in that. It only becomes sad if you cease to WANT to try, and don't want to remember any of the places where you might talk about what is going on, and maybe get some help.
Embracing, you ask about your Christmas do - well you have many choices: you could go and have a horrid time, get smashed and have a worse time; or you could stay at home, feeling bad about yourself, get smashed on your own and have a horrid time. Not much difference between those two in terms of how you feel emotionally and physically the next day, pretty crap on both fronts, and a waste on money too. Swings and roundabouts really.
Or you could choose and select from as many tactics and strategies as you can find on here or think up, or borrow from other people, and you could get yourself out there, find ONE person who will be sober (the driver, the pregnant friend) stick with them, stick with a selection of non-alcoholic drinks, laugh at the others as they get drunk and become argumentative, and stupid and thank your lucky stars that tonight that is NOT you. Then go home, and know that you can have a night out without booze - may not have been the best fun (Christmas parties often aren't), you may not have dazzled the world with your wit and humour but the world will be too busy nursing a hangover and wondering what on earth they did, but you will be able to go to bed with pride in yourself.
Or you could apply those strstegies in an alternative way - get a friend to come over - one who will not need to get smashed, have a good old gossip, make christmas decorations, have a hand massage or a makeover. Anything. But do have a contented and sober evening, and feel good about yourself.
What I am trying to say (in my longwinded way) is the choice is not reallly about whether you go to the 'do' or not. The choice is how you stay sober for that one evening.