Emmy he is a nasty, angry, mean, spiteful abusive man and I had to swallow hard reading your post bc he sounds so much like my nasty angry abusive xAH.
You try and be civil and want to cooperatively co parent and you think of you're civil he will be too right? Logical. But he is full of rage and darkness and self loathing and he can't be civil or responsible or cooperative and will time and time again lash out at you like this.
I'm guaranteeing you in a day or two he will be sorry and kind and you'll think "this time he can a civil" and you'll try again to co parent w him and he will repeat this cycle again and again.
I'm so sad for you bc I know how you're feeling and have been there too many times to count.
Hard as it may be, just limit any contact to text or email and communicate only about the most necessary stuff.
He's living at the house so he can figure out the bills. It's not your job to help him manage life as a grown man. He is using the talk about $ as a way to suck you in and rage at you about something. My xAH does it too. He will ask an innocuous question and I would answer and next thing I know he's raging at me.
I don't reply anymore to things that aren't directly related to my kids and I have a court order saying that's the limits of conversation he can have w me.
Have you seen a lawyer? Maybe you could get a protective order or something to keep him from contacting you.
I'm so sorry for your pain. Your kids are lucky to have you and you don't deserve your ah's crap at all.