I suggest you are at the beginning of a very new situation and are being too hard on yourself. Being a single parent is no easy thing in the best of circumstances and when you throw in alcohlism it's even worse. Watching your marriage fall apart and maybe end is never easy under the best of circumstances either.
You can do this. You will do this. And end up in a better place.
Trust in the Lord with all your heart, and do not rely on your own understanding. In all your ways acknowledge him, and he will make your paths straight. Proverbs 3:5-6