How wonderful! It's so good to hear you say that!
You can do it! If not for yourself, for the kids! All of those thoughts in your head telling you you can't do it, you wouldn't make it, you couldn't support the children, it's too hard for you, and on and on - those are HIS WORDS in your head, the result of the years and years of him telling you you're not good enough. But YOU ARE good enough, and you CAN do it. He is full of shit, right to the brim!!
Just remember, keep your plans to yourself (totally hidden from him) until it's time. This is SO important!
You don't want him to get advance notice and talk you out of it, because he WILL NOT CHANGE no matter what he says when faced with the possibility of losing his stress ball. He may turn on the charm for a couple weeks, but he will go right back to his rotten self soon enough, and then he'll become even worse for having found out he could lose you.
And you most definitely don't want him to find ways to prevent you from going through with it or give him time to hide assets to fuck you and the kids over down the road.
Don't let on that anything is amiss. Don't change your outward behaviour toward him at all if you can help it. Don't talk about this to mutual friends or anyone you think might ever let slip. Keep it between you and your most trusted personal support network.
Do ALL of the footwork while he is out of the house. Dig and snoop and find all of the paperwork you can - it's your home/money too, and don't forget that. Take photos and get copies of all financial and asset documents. Keep a meticulous diary of his abuses, and keep it well hidden.
Read the other threads on this site. They're overflowing with wonderful advice, from people who have been exactly where you are and come out the other side doing great. Don't be afraid to ask questions, even if you think they're stupid questions (they're not - that's his opinion, not ours). MN can and will help you. We're here for you!