Something being legal doesn’t make it right.
It makes it legal and therefore presumably right in some people's eyes. It may make it immoral in yours, but that's you not everyone.
Something being illegal doesn’t make it wrong.
It makes it illegal and breaking the law is definitely wrong.
Bad law makes problems worse, not better.
It's not a bad law to protect the rights of biological women.
Luckily, we live in a democracy.
So use it! Try and get the law changed to let you into women's spaces. I don't think you're going to succeed and personally think you should be campaigning for 3rd spaces, but of course that doesn't suit the trans activist agenda, does it , because what you are really demanding is the affirmation of society that you are female. You'll wait a long time for that one.
If the law isn’t fit for purpose it can be challenged and changed.
But it is fit for purpose for the vast majority of people, and that's how democracy works, sadly for you. It's a lack of gender neutral facilities other than using the disabled ones that's the issue, together with the determination of some strident men to force society to accept that they have changed sex, not the law.