I agree with the others. Phone Woman's Aid NOW. They'll find somewhere you can stay whilst they sort you out. My Mum went into a refuge when I was a child (with my brother and I)... It wasn't that bad. And the abusive partners weren't allowed to know where we lived so we were safe.
You need to get away from this bloke. He's not good for you, your baby, or your children. I wouldn't tell him you're going either, just pack up your stuff and go whilst he's at work. A women's shelter will be able to offer you all sorts of advice, help etc.
(((((HUGS)))))