Feeling that your body is wrong AND that people are defining your existence using a surface-level impression of the parts that are making you sad can also make you (even more) sad.
I'm just trying to tease out what this means, butterfly. It isn't intended to be hostile. I just wonder about the rather dramatic way in which you speak of others' perception.
What does it mean to 'define someone's existence'? Do you mean 'recognise you as male'? Maleness isn't a destiny. You can still be anything you want, including a transwoman. Most people, including most GC feminists (certainly me) would absolutely endorse your right to live as a transwoman, to define yourself as such and to present in whatever way seemed to you to express your sense of being female. So in what sense do we 'define your existence' if we simply accurately perceive something about you that makes you sad?
Use of the term 'defining your existence' presents a simple and involuntary moment of perception as if it were an authoritarian and aggressive act.
Sometimes the trans movement (I certainly don't mean you, butterfly - I have only read one or two of your posts and haven't a clue how you feel about what I am going to say next) reminds me of a strand within the incel movement. Incels often seem to present women as being hugely powerful, just in virtue of the fact that men need women's bodies and women are allowed to withhold them. Just having sovereignty over ourselves (our bodies, our perceptions) is perceived as a form of control over men, because it presents an obstacle impeding the gratification of a need.
I hope you can understand, butterfly, how commonly women experience a man approaching them in some way and requiring compliance to their needs. Not just in the extreme way of rape, sexual assault, flashing, lewd comments, but in a million smaller ways. Unwanted approaches, superficially friendly comments, that we have to respond to smilingly, endorsing the man's ego, as if flattered, in order to forestall their angry perception of us as (to use some of the comments typically thrown as woman) cockteasers, frigid whores, stuck up slut, etc.
This is the context in which we are presented with an additional requirement -- to fully perceive a transwoman as female (not just to use preferred pronouns etc but to go further than that in order to avoid being seen as 'grudgingly humouring' as butterfly puts it).
This requirement comes on top of a huge pile of life experience in which we have been required to second-guess ourselves, defensively misrepresent our reaction to male people.This is order to keep ourselves safe from overt or seething anger from those who 'define our existence' as if we were simply the means to (or the obstacle to) the gratification of a desire.