Oh gosh this sound so difficult and I totally get it's a huge huge thing to call the police and will take a lot of motivation to do it. Just don't let him talk you round that's what abusers do - he's making it sound like it's your fault. It will happen again and you have to protect your kids more than anything. Children will often pick up eventually that abuse is happening and it is harmful to them. And you deserve better yourself.
Why don't you call one of the national helplines when you're alone today and get some professional advice as they will guide you through legalities if you do call police or move out.
www.nationaldahelpline.org.uk
Just call them and then you know that you're taking steps to get away even if you're not calling the police cold turkey