Sally, don't beat yourself up over this which is all too easy to do. I only joined the site today (and not quite sober yet) so may not qualify to give advice right now but have had ongoing problems for many years so know how you feel.
I know the guilt will be excruciating at this moment and the evening is probably going to be a long one. Get rid of the brandy because that'll make things ten times worse. Can you phone someone to pass the time and just to distract you. Be strong. My thoughts are with you.