My heart goes out to you and your children and I want to assure you that God knows all about your situation and wants to help you. God's promise is true: "When you pass through the waters, I will be with you" (Isaiah 43:2).
What your husband is doing is very wrong, and God doesn't want you to put your life and the lives of your children in danger. Although God's perfect plan is for marriage to be a life-long commitment, nothing in the Bible requires someone to stay in a life-threatening situation -- not at all. The Psalmist prayed, "Rescue me, O Lord, from evil men; protect me from men of violence" (Psalm 140:1). When society grows corrupt, the Bible says, people will become "abusive...without self-control, brutal, not lovers of the good, treacherous.... Have nothing to do with them" (2 Timothy 3:2-5).
What should you do? I suggest you begin by insisting that you and your husband get professional counseling (your pastor may be able to suggest a trustworthy Christian counselor in your area). If he refuses, however, you may need to explore a legal separation (and perhaps a restraining order, if he threatens further harm). I'm not a legal expert, of course, and you should seek legal advice about these steps.
Most of all, I urge you to turn to Christ and commit your marriage -- and your whole life -- to Him. God loves you, and although you're in a difficult situation, you can trust your future into His hands.