I'm not. It won't surprise you to hear that I've never once stood outside a ladies room. And sure, if what you were saying were even close to true, and women got to decide who they recognised as belonging in that space, that would be great. But this is absolutely not true.

In fact, funnily enough, I recently saw this poster specifically admonishing women NOT to speak up if they recognise somebody in their spaces who they think doesn't belong there (https://twitter.com/francesweetman/status/1561695348686462977).

As for whether "I find out that I'm not the gender I thought I was," I literally have no idea what you're talking about. This, to me, sounds like saying what if you find out you're not the height you thought you were or your skin was a different colour than you thought it was? Gender is not the solid thing you seem to imply. I'm masculine in some ways, feminine in others, and this has no bearing on the fact that I'm a male bodied human being which, up until recently was uncontroversially known as a man. If you're up for it, I'd love you to explain this in more detail. The way some people talk about gender today makes zero sense.

Now, of course, I don't have gender dysphoria. And I'm not in any way trying to deny that gender dysphoria exists. I'm simply saying that when you move beyond "let everybody live their personal lives however they want" (which every decent person agrees with) to "change the norms and boundaries of women in a way that lets men come into their spaces" I think you need to be a little more intelligent than asking "well, who 'feels' like a woman today?" Especially in a world where males, whether trans women or men, commit ~99% of all sexual assault.