S- Welcome, Sorry you are here, but you have come to the right place. When you are dealing with an A in your life they consume you. What you need to do is start taking care of you and your little sofedups'. Once you stop worrying if he is drunk, looking for bottles or when he gets home, what ever, you free up your brain for important things of what to do next.
Reaching out to an attorney, like Lexi says is a great idea, ask if the first visit is free. Find out about leaving him, renting the house, paying the bills, and all the financial questions. Have a ton of questions that you can ask. Find out about letting him take the kids if he is drunk or even driving drunk. He is going to be very angry. You need your family support. All I am asking, make sure you are 100 % committed to leaving. If you are just threatening to get him to stop, he will stop for a day or two, you go back and then he will do it again. You need a time frame of 6 months sober before you go back. So if you are not ready, don't threaten. Get all your stuff together and figure out a plan.
At that time you execute the plan. You are in no hurry as I am sure he is going no where. Hugs my friend, we are here for you, ask away and we all will help you do what is only best for you and your kiddos!!