Thank you for your advice. My SO and I discussed this recently and have agreed to try our best to help each other out.
How exactly do you act once you become angry and upset? Lashing out, blaming, passive-aggressive?
I become controlling. Having plans changed on me suddenly and in a way that I feel is dismissive feels like it takes some of my autonomy away from me. And then I become controlling. It's really stupid things like demanding hugs or sitting up and talking or that we eat at a specific time - none of which are normally important to me.
This causes specific problems because my SO for very understandable reasons has a similarly problematic emotional response to being bossed around.
It can be hard for both of us to take a step back and be reasonable with each other. But your advice to take a step back and try not to react with annoyance is good - we often do best at discussing these things if we are able to wait a few days (mostly because I am able to be more reasonable about discussing what happened).
We keep trying and we think we are making progress with it.
Thanks for all your thoughts and advice. I will keep all of that stuff in mind.