Lol. Don’t worry. You will find women who enjoy kinky sex but also are completely monogamous. I’m all for polyamory, honestly. I do believe that it can be an extremely fulfilling way of life. But the way your ex was making you feel bad or weird for feeling differently is really sketchy. It’s good you guys broke up.
The excuse that humans are meant to be poly is just a pretext to allow her to cheat. It is good that you split.
It is normal to want a monogamous relationship, especially if you see a long term future in your relationship. If your SO still wants to experience other partners I suspect that she is not looking at your relationship as “the one”.
You both may be at different stages in your relationship and this might cause problems. When one partner does not keep up with the other in the growth of a relationship it will typically create a feeling for the one that is ahead that a clock has started ticking and if the other person is not willing to catch up, the clock might run out.
I think you both need to sit down and re-evaluate your relationship together to make sure you are both on the same page.