Huge sympathies - not what you wanted when you were looking forward to a shared anniversary celebration.
It sounds very much as if he is an alcoholic - it's not going out with mates and coming home drunk, it's drinking at home without regard to his family responsibilities, and out of control.
Doubtless he will be full of remorse and self-loathing tomorrow morning. He probably DOES love you and the kids, but while he is an alcoholic he can't choose to prioritise you, his need for drink has him unable to.
I would tell him tomorrow morning, in a quiet but absolutely serious business meeting - having accepted no lovey dovey apologies - that if he takes direct action, THAT DAY, to seek a means to get support to tackle his alcoholproblem e,g makes an appointment with the Dr (for starters) you will do all you can to support him to get himself under control. You could spend the evening now researching alcoholism and support servoces in your area, and signing up to the family branch of AA - where they offer support and advice to the families of alcoholics. Tll him - if it is what you want, and if you are genuine about it, that you will support him because you love him, and want to save your family life and your relationshipas well as him, his health etc.
However, if he refuses or prevaricates or tells you you are over-reacting, then either be prepared to tell him to leave and not contact you until he has tackled his drink problem in which case you will re-consider, OR know that you face a life of hi being unreliable, getting worse, drinking away your money, causing humiliating incidents (being drunk around the kids in the day will not go unnoticed unless you live as recluses, believe me), constantly protecting the children f the outfall of his drinking. and never being confident to leave them with him. And loneliness and isery.
I know. One of my best friends stayed with her alcoholic dh 'for the children' and it has been wretched. Especially as she was deluding herself that the children benefitted. rthey didn't . They knew, they hated his drinking, and as they grew older were multiply embarrassed by it.
Good luck.
So sorry about your anniversary night 