Feeling like an asshole for saying no

So: I’m (34m) in a dynamic with my Domme (36f). It’s not a romantic dynamic, and she has a primary partner in her wife.

Our dynamic encorporates occasional play and a more ongoing service/finsub thing. I enjoy both parts. Yesterday we met for coffee and she pitched an idea to me: that I’d be kept in chastity for a week and that my finances would be cut back to the barebones, including limiting myself when seeing friends for that period.

Although we had discussed a couple of these things before and I’d expressed an interest, the idea of having so many things curtailed at once (especially socialising) made me feel quite nervous, and I was worried I might end up being triggered during the time.

She picked up on my nerves, and got quite upset that I wasn’t as crazy about this idea as she was, and I feel bad. She had mentioned that my rejection made her feel unseen as a sadist, and that I was only interested in my own fetishistic type of play. I mentioned that, given time, I’m sure I could feel less anxious about it and come around to the idea but she mentioned that if I asked her for it, it would feel like being a kink dispenser.

I feel like I’ve fumbled something that might have been fun because I got anxious, and I made her feel terrible and I feel terrible about that.

Any advice would be appreciated.