Please be careful sweetheart.
You have taken a brave step but an abusive controlling man will not give up that control easily. When he realises that the "nice guy" act isnt working he will revert to type and the nasty will come out, but bigger and nastier.
Pack an emergency bag and keep it safe. All of your and the kids documents, any financial stuff you can get and any keepsakes that you couldnt bear to lose. I know that one is hard but think of it as "You are in a fire and you can save three things...." and pick those things.
Keep that bag away from the house if at all possible. Then change all passwords on your phone/laptop/Social Media/Email....everything. If you have apple phones turn off the cloud thing that updates connected devices and turn off your location finder.
I dont want to scare you but I have seen this play out too many times to think "Oh well, when he knows I mean it he will just go".....HE WONT. He will fight, bully, fight, shout, bully, scare....and that means the kids as well as you. "Mummy is making me leave, you dont want me to leave do you? Its all Mummys fault, I dont want to go, I know you hate mummy making me go...." Been there done that, had the therapy.
Prepare for the worst, hope the best. Always have a plan B and then a plan c...d....e...f....