Definitely call the police and report his threat to kill you and DD.
Then phone Womens Aid and ask them for help and advise. They deal with this kind of situation daily, so will be a valuable resource.
Change where Child Benefit gets paid into if it's his or a joint account. Take half of any money in joint accounts/savings.
Get your parents to go with you to your house when he's not there to get any passports/bank statements/ Birth certificates /laptops/ kids stuff etc.(Get meter readings to send to utility companies as final readings too if your name is on the bills) Make a list before you go to make sure you don't forget anything.
Take your name off any bills associated with your house e.g Gas/elec/ council tax etc, telling them you have moved out. Do this by phone and confirm via email.
Next get an appt with a solicitor, and get advice from them in what steps you need to take to begin divorce proceedings and in how best to get the house sold.
It might take a long time to get the house sold etc, and it may not be in your interests to try to move back into the house as he wouldn't be likely to abide by any 'non-molestation' order etc, especially when drunk, and you really don't want to put yourself or your DC in harm's way by living alone where he can easily find you...so assume you've moved out permanently. Now you're in the process of starting fresh.
Then I'd be thinking longer/medium term i.e Registering with council for emergency/permanent housing, applying for all benefits you may be entitled to e.g Universal credit, Child Tax Credit etc
Once you have some income, you could save up for a deposit etc and rent (You'd be entitled to help with rent etc through benefits)
You've done the hardest part, now you just need to keep moving forwards...