When you enforce boundaries, the other person will get angry because you're following through and standing up for yourself.
My W got pissed off me too in the beginning when I didn't just roll over for her. I know it's hard to keep your strength and composure in the beginning, but match his anger with you being calm and cool. It will have a huge effect.
In this situation, take your kids and just leave the room. if he gets abusive, then call the cops. I know that you probably don't want to do that, but you have to think of your kids. Him yelling at you in front of them is very traumatic. I remember those episodes with my parents and till to this day it reminds me how scary it was and how I felt helpless being such a little person.
Don't back down from your boundaries. They are in place for you and your kids. If he's going to go unhinged, he'll have to face the consequences. If he continues yelling at you even with you enforcing boundaries, I would seriously consider contacting authorities and getting help. Vanilla has amazing advice if things get more abusive and she'll be able to tell you what you can do.
