Zappy,
The absolute best thing you can do for yourself and your family right now is go to an Al-Anon meeting.
There are on-line meetings as well. Get a copy of Courage to Change, it's a book of daily meditations that have helped me tremendously to start my day with a healthy, realistic focus.
I really feel for you as you seem to believe that so much rests on your shoulders. And I know it feels that way, but please take care of yourself. It's the only thing you do have control over.