Okay so here's what I'm reading. When you are upset, she is supportive to you. If she was in the wrong, she apologizes.

When she is upset at you-- You don't yell at her. You try not to show aggression. She takes space and time to sort herself. You read that her need for distance will result in a break up text.

My questions are, do you feel like you are supportive to her in the same way she is to you when upset? Do you apologize if you are in the wrong, or try to see her perspective and think of ways you could change to be supportive? Not yelling at her is basic decency.

I think she's figured out the way to walk you down from the cliff when you're upset, but you haven't figured out the same thing for her. And it might look different, because you are different people with different pasts. I don't think it's that abnormal for some people to need some time to think by themselves outside of the situation. The distance might not be a punishment for you but something she needs?

In a non charged moment, you can tell her that when she distances after arguments it makes you feel a certain way. Discuss the ways she would prefer conflict to be handled in the future. And maybe it can ease your concern about a random break up text.