Ok, let me ask this: why do you have to talk down your son? Let him go. If he's mad, let him go off and be mad. It's not your job to talk him down. XH is pushing his buttons and he's choosing to react to that. That's on him.
If he's laying into you, tell him you won't be talked to this way and you want to be treated with respect. If he has a problem with his father he needs to find a way to deal with it without laying into you. You're not involved.
I've seen my own mom do this with a sibling when a sibling gets really upset over my dad, and my mom gets herself so in a tizzy trying to talk the sibling down that she gets bouts of IBS and that morphs into diverticulitis.
As a result, we are all trying NOT to "go to mom" when dad gets us upset...it's a type of codependency that is rampant in our family and we're starting to see it actually is bad for my mom's health.
But I've also said to my mom privately that SHE needs to start telling US that she just isnt' going to engage in talking us down, because it's a crossing of a boundary and a type of codependence.
M45 Bomb 6/09; EA 6/10; Divorced 1/11 Proud single mom of 7 little feline girls and one little feline boy "Fall down 53 times. Get up 54." -- Zen saying