A Heavy Burden of Trust Breached

I've been in an age play dynamic with my partner for a couple years now. It's something we both enjoy and consent to every time, but there was this one incident that I still can't shake off. We were at her place, everything seemed normal as usual, but after our session, she mentioned wanting to try out another aspect of the dynamic she had been thinking about for a while. She wanted to explore being in charge in my little space more directly than before. At first, I was hesitant because we always keep things within comfortable limits and communicate openly. But over the course of a few weeks, I found myself getting used to her new approach, which included some discipline as part of our play. It felt like a natural progression at the time, but then there came this moment where she took it further than any of us had intended before. We were both aware that boundaries and consent are non-negotiable in our relationship, yet that night, I didn't voice my discomfort clearly enough. I feel really conflicted about what happened next. She acted as though something was wrong with me for not adhering to her commands perfectly, but part of me also felt responsible since we both agreed on these new guidelines beforehand. It's this gnawing feeling that if I had stood up for myself better, maybe she wouldn't have taken things so far. But then again, am I the asshole here? Or is it more about us needing to re-evaluate our dynamic and boundaries in a clearer way?