Sounds like he's trying to control you, and now it hasn't worked he's upped the ante.
Keep him calm for the moment. When you feel safe make sure you prime somewhere to go - a friend or relative.
Get your financial ducks in a row. Get passports and financial docs, evidence of his earnings and joint assets etc.
Keep a bag packed with emergency kit - clothes, money etc to make a quick getaway if he kicks off again.
Call 101 and tell them that you feel at risk. If he does kick off you'll be a priority number and the police will respond faster. Also call Women's Aid. They're very busy, but if you are being abused they are the experts in helping you to extricate from a potentially explosive situation.
Tell someone in real life that you feel threatened. Talking about it will make it more 'real', especially when he turns on the Mr Nice Guy act.
Do what you need to do to to make you and the DC safe.
Sort out a solicitor over the next few days. Speak to 3 or 4 for the free half hour and find one that you're comfortable with and is an expert in famil law.