OP, I'm sorry you are going through this.
I am an alcoholic and working actively on recovery. My DS (adult living with me - just the 2 of us) has found it really difficult and is very very supportive of me.
Have you looked at getting any help for yourself from Al-Anon? It's specifically to support the families of alcoholics.
AA is not the only resource available to your husband (and if he's anything like me, he won't like the idea of a group, particularly with the religious overtones of AA.)
I access help through my city's Addiction Recovery Service. If you google "[my city] addiction recovery nhs" you will probably find that he can self-refer.
However - you cannot do this for him. You cannot force him. If you give him an ultimatum of "it's your family or the booze", you have to be prepared for him to pay lip service to getting help but then him being dishonest and not keeping appointments, drinking in secret etc. He has to want to change for himself.
Ultimately you may need to leave, and that may be his rock bottom, lightbulb moment that makes him realise he needs to get sober. But it also may not.
I agree with a PP about asking MN to move this post to Relationships before the crowd of cranky AIBU denizens wake up and shit all over it. Just hit "Report post" on your OP and ask MN to move.
Ultimately your main job here is to protect your DC. Have a google of "adult child of alcoholics" and you'll find a huge "laundry list" of common characteristics of children who've grown up with alcoholic parents. You do need to demonstrate to them that the behaviour isn't normal, isn't acceptable, and shouldn't be emulated. Being honest with them will help (as long as you make it age appropriate) but be clear that you're criticising the behaviour, not their dad as a person.
So "Your dad made some bad choices last night about drinking alcohol" - not "your dad is a pathetic drunk".
Just to be clear, him continuing to drink doesn't mean that he doesn't love and value his family. Alcohol is a bitch of an addiction, it really is.