HI, My name is Angie, I have been married almost 15 years.
A period of separation can provide a much needed break in a tension-filled relationship. Your pastor and/or a marriage counselor can help you make this time apart productive and beneficial as much as possible. My personal advice to you is make sure you take any personal papers with you when you move out: i.e. SSN cards, insurance policies, bank statements, etc. If you have a joint account with your spouse you may want to seek advice on taking money out and opening a separate, sole-owned account. (Your spouse has a legal right to withdraw and close any joint account you may have together. As do you.)
I'd also be very clear on the "rules" during separation, i.e. no dating others, no DUIs, etc.
In fact, I'd encourage you to reach out to Alanon.org. This is the sister organization to Alcoholics Anonymous. Alanon and Alateen.org are for the friends, family, and children of alcoholics. They can help you both cope with your husband's drinking and help you not to encourage or enable it. (And the first thing they'll tell you is not to try to "treat" your husband on your own or believe his claims he's not an alcoholic.)
Don't shy away from accessing this wonderful organization. They can help you keep your sanity and help you make good choices about the future, especially when alcohol is in the picture.
Be very realistic about your legal options and rights. Many a woman has moved out of the house one day and found herself served with divorce papers the next. So be careful what you agree to do.
It's good that you are going to see a laywer because I think you need to get the financial picture spelled out clearly--who is going to be paying what expenses and are you going to be paying him child support (which he is entitled to since he will be the custodial parent).
We will be splitting custody of the kids with me having them for 4 nights a week and he for 3.
I don't know if he has it in him.
Well you should consult an atty--you would be entitled to child support and possibly alimony, but it depends on the laws in your state, how much money your DH makes and how long you have been married.