If you can stick with Alanon, you will ultimately find it a huge source of support - sometimes it's a good idea to attend meetings at a variety of groups. They are all different and it is inevitable that you'll feel more at home in some than in others.
Where Alanon really scores is in helping you to detach from the alcoholic, with love, and this will help make your life manageable if you don't want to divorce. It will make it easier to discern what is and isn't your responsibility - useful stuff whether you stay with him or not - which means you needn't get sucked into the craziness that living with active alcoholism entails.
You are right to be concentrating on yourself and your own wellbeing right now, but there's no need to announce it to him - just do it! If you can take care of yourself and your children, and let the relationship take care of itself you may well find that taking an actual physical break from him (so you can go back to more of the same) becomes an irrelevance.
(((HUGS))) and good luck with all this!