My daughter was about 4 when she pointed out the obvious physical differences between 'mummy' and 'daddy.' Biological sex is a physical reality and it is nonsense to deny it and harmful to both sexes, but to women in particular.
Gender is a bullshit social construct. I wear pretty dresses and make up, and I like pink. I also do DIY, out-earn my husband and work in a male dominated environment. I am a woman with my own personality, likes and dislikes who refuses to be bound be gender expectations.
A person with a penis may dress how they choose, be called what they choose, live how they choose, love who they choose, and I do and will 100% support their right to do so. But whatever choices they make, they will still be male - neither they, nor their penis, is or will ever be female.
It should be OK for people to live how they choose. But it should also be ok for me to say that there is a fundamental biological difference between us, to say that I am a woman and you are a man and because of those innate differences I don't want to share a hospital ward, or a prison cell, or a domestic violence refuge with you. When we segregate by sex it is your genitals which make the difference, not your identity.
If you feel unsafe in male spaces because you have chosen to have a feminised appearance then that is awful, and wrong, but you need to tackle this by tackling male violence and entitlement, not by displaying that same male violence and entitlement by imposing your male body on my safe space.
A person with a penis is not a woman. A penis is not female. And we should be allowed to say this.