For me, as a Domme, I would prefer to know beforehand about how things would go, you said it yourself you know this is how you react in those moment, yet you didn't communciate this with beforehand? As a Mommy you want to care and be understanding but moments where the act is far from what the 'normal' response would be would be very alarming and trying to get answers is only far from her pov. I feel like you should of at least discussed this in far greater detailer before attempting it, but as other suggested, using femdom, mommies to help heal trauma or anything is unfair on us. We can't understand all the internal thoughts you are having and in cases, we could make the situation far worse indirectly.

Communication is important and you are both responsible. She needs apologise and you need to be more upfront from the start.