I don’t think she’ll be mad. She won’t even be disappointed. She’ll probably want to investigate why, so that when you move forward you guys can work on your triggers together. That’s all it is, after all—something must have really bothered you a lot today or yesterday or last week. It’s not so much your fault as something to learn to manage better and better as time moves forward.

I did the same thing recently and had to go back into therapy. It helps to be honest with them. My therapist implemented plans for me to relay to my partner to keep me safer. As well as ways to calm down when I feel I need to do that

Same here, in the waiting room now, it'll be ok I promise

I did the same thing 3 weeks ago and had to get 20 stitches. But slip-ups are part of the journey to getting better and do not mean failing, like a song I love from citizen soldier "my scars are my war paint" they show all the battles you didn't succumb to and you'll beat.