Healing...The guilt really does ease over time. It's also important not to listen to others (e.g., neighbors, family members) who make guilt-inducing comments, such as 1) how could you leave a person who is so sick and helpless, OR, 2) why in the world did you stay so long?
No one knows what it's like to live with an alcoholic...except the good people on this forum and others who've endured the nightmare. Trust your gut, especially your maternal instincts that told you, wisely, to get your kids out of that situation.
Give yourself a few months. The FOG will lift, and you'll feel much better about your (very necessary) decision to save yourself and your children.