Call the police, report the what he's done to you, and get the contact information for the nearest domestic violence support group in your area.
You need help getting ird of this guy, before your kids learn how to abuse their partners. It's your job to show them this is NOT acceptable, and that you can stand on your own two feet.
Tell the police, testify against him, and if he threatens you, tell them again.
There is nothing appropriate about trying to stay with a guy who does this even once. There is nothing you could do to deserve it- it's about power, not love, and he needs to be gone. And that means YOU have to do something about it.