puddleduck Don't be embarrassed,you are not weak - you are posting on her and giving this a lot of thought.
You are absolutely NOT being irrational.
Do you think your gut instinct - inner voice- is trying to tell you something?
The last time he did threaten to kill me
That is serious,and unsafe.
That's why it has stuck in your memory.
If a drunk man threatened to kill you in the supermarket/at work/the car park I am sure you would not have him to stay in your house ,look after your dc,or leave your dc at home with him...?
I hope you have made it clear that he MUST NOT drink in your house?
Please,do not sleep at a friends,leaving your dc alone with him.
Please get some RL support - Womens Aid can advise you.Do you have a solicitor to help arrange formal contact?
I really think this situation is a risk to you and your dc and that you need to take some some action.
Take care of yourself and keep posting.
Don't let him stay again.