I'll bite. Do you think that anyone who says they're a woman definitely is one super-dandy?
To put it the other way round, if I say right now that I'm a man (even though nothing about me has changed or will ever change), am I one?
Even after I change my body and wear different clothes and have a different name, am I really one?
I'd argue no in both cases; I don't know how you'd feel, but to me you can't switch chromosomes or really change your biological function, and you can't just will yourself out of social conditioning either.
Getting past that; having declared that I'm a man, does that mean I get everything that biological men do and tell them what a man really is?
If men had limited equal opportunity resources like scholarships or refuges or sports, or same-sex relationships, should I instantly get access because of my announcement? And demand that gay men accept me and reframe themselves and their own sexual preferences because of me? Do I get prostate tests and medical care as a man?
This is where gender critical people get cross, because of course you can act like you're a man/woman and society can be kind and accept the social lie with you.
But you're not actually one and shouldn't take resources away from those who need them or lecture the group you're identifying with. You need your own needs met and your own new areas of care and provision.
If this hurts you then you need mental health care to help you through, because we literally can't change basic biological facts. Anymore than we could wish away the gravity or mathematical truths.