We've gone through this already. Why do you keep asking the same questions and ignoring everything we say?

Your brain is a part of your body. Having an atypical brain doesn't make you the opposite sex. There are some men that are shorter than many women, but that doesn't mean these men are women either.

Convincing your goverment to change the sex markers on your documents doesn't make you the opposite sex. If, somehow, you convinced your goverment to change your birth date because you say you're 10 years younger, that wouldn't make you actually 10 years younger, either.

Sex is about reproduction. We're an anisogamic species, which means we reproduce through the production of specialized cells with half the DNA (gametes) of different size. Male individuals are the ones who produce small gametes (spermatozoon) and females are the ones who produce large gametes (ovum). Then, a spermatozoon and an ovum fuse to form the zygote, restoring this way the normal amount of DNA. Some species are hermaphrodites, which means they can produce both male and female gametes. Humans are not hermaphrodites, though. In humans, there are several genes involved in the process of sex determination, but one of the most important is the SRY gen. If this gen is present, then the embryo will develop testes. If not, then it’ll will develop ovaries. The hormones secreted by the testes drive the male differentiation pathway for the rest of the male reproductive organs. And the absence of these hormones drives the female differentiation pathway. As the SRY gen is located in the Y chromsome, XX individuals are females and XY individuals are males.

There are some people who have a disorder of sexual development (DSD), but they are rare and they are still either male or female, i.e. they don't produce a third type of gamete.

We don’t need to examine someone’s chromosomes or gametes to tell their sex. Secondary sex characteristics don’t define sex, but they are usually a good way to tell someone’s sex. We have evolved to be able to tell the sexes apart. If we weren’t able to say who kind of humans are able to get pregnant and what kind of humans can impregnate the former our continuity as species will be quite complicated.

Humans can't change their sex. Neither naturally nor with the help of medical technology. There is not such sex change. What "medical transition" can only do is to create a simulacrum of the opposite sex through exogenous hormones and cosmetic surgeries. However, every one of your cells keep having the same sex chromosomes you've since conception not matter how much exogenous hormones you take and not matter how many surgeries you undergone. Although hormones and surgeries may affect your fertility, you don't suddenly start producing the gametes of the opposite sex. BTW, both males and females have the same sex hormones. The difference lies in the concentration levels of them. Also, the hormonal profile of females is more complicated because it varies through our menstrual cycles and through our different life stages. Lastly, more often than not, we can tell your actual sex.