*Brain sex is a fundamental tenet of trans ideology. They tell us that they have a 'mismatch' between a female brain and a male anatomy, and that the gender identity corresponds to the sexed brain, which takes precedence, and represents a body that was 'born wrong'.
Feminism tells us that the brain, like the liver, heart, kidney, etc., are human organs, not female or male organs, and that the differences between men and women arise from chromosomal and hormonal differences, and socialization; and that there is no such thing as a 'female brain', just a human brain that is located in a female body getting female hormones and (under patriarchy) feminine socialization; and a human brain located in an male body getting male hormones, and (under patriarchy) masculine socialization.*
First, the fundamental flaw here is that you're expecting science to meet your political and social beliefs. Science (when done properly), starts with data, and draws a conclusion from the data, not the other way round.
Second, you concede that female hormones such as oestrogen are more present in the female body. We know that hormones impact behaviour (I'm sure you wouldn't argue with the role of hormones in making us feel hungry and seeking out food, for example). Since we know that hormones impact behaviour, I'm not sure why you find the idea of a hormone like testosterone causing aggression and higher libido so controversial.
You live in a society that obsesses over sex, hypersexualizes and objectifies women, and pushes both men and women to regard sex as hugely titillating. You are also, presumably, a sexually functional human being who is liable to be sexually aroused by sexually explicit material.
I'm not buying this. Yes, I live in a society in which sex is hugely titillating, and yes, I definitely saw that as a child (although didn't girls see the same stuff? Never mind). But I remember going through a phase, aged 10 - 11, in which it seemed like everyone around me was having their first experiences with girls, but yet, I had absolutely no interest. I was worried for a long time because I thought it meant I was gay (homophobia was a lot more common where I live, and back then). Anyway, by the time I was 13, I became a lot more interested in girls, and I was having sexual thoughts about them all the time... but it's not like I'm consciously choosing to have those thoughts, they would just happen without me even knowing. To me, that's not the type of thing that's conditioned, that's a lot deeper... ultimately, I attributed it to puberty. Given the nature of onset, and the timing, I can't fathom how it was due to conditioning in society... if it was conditioning by society, I would have been interested in girls aged 8 - 11, because I saw those messages a lot in my childhood... but yet, it didn't happen until age 13, which, funnily enough, is when you would expect a surge in testosterone in a teenage boy.