> He says I'm making a decision based on anger that's I've essentially been pregnant for 14 months now.

NTA.

> WIBTA if I agreed to be steralised - taking away also his choice of having any more children - because that's what I want?

NTA.

These are both forms of emotional abuse. They're subtle and most people wouldn't see it. In the first example he's telling you your emotions aren't what you feel by saying "you're just angry", basically undermining how you feel with his own opinion. The second one he's holding not having more kids above you, at least in the form of the guilt you're displaying. I'm not blaming the man at all, he may just not see how it's affecting you. Your body, your choice.