Hey buddy, I am female, but I too struggled with what I thought was 'gender dysphoria', long before there was a mainstream term for it, pretty much all of my conscious life, from about aged 9 to now (I am in my mid 20s). I had all of the traits and symptoms of the mental illness, but I made the mistake of believing that it was an immutable quality, and that it was a discrete quality disconnected from my past. These are both untrue. I tried transitioning, desperate for the kind of peace that I felt as a kid before I was in mental anguish over sexual dimorphism and gender roles. Before I started healing properly I was constantly angry and miserable, I hated myself and if I wasn't a violent and aggressive butch, I was dissociated and barely alive. I seriously considered suicide for most of my life. I'm not saying this for pity, or for any kind of clout, merely to establish that I understand how GD feels, and I know how crushing it can feel. I took exogenous testosterone for 3 years; at first, it seemed to help the incongruence, but it only treated the symptoms, it did not treat the actual mental illness.
Let me tell you here, transitioning can not, and will not, bring you the peace that you seek. I am still mentally fragile even all this time later, and I have had moments where I've had episodes of mental relapse into experiencing this profound mental distress of looking in the mirror and not recognising myself, of feeling that what is natural is truly "wrong" but trust me when I say that it does get easier. You can heal from this.
Firstly, take time to examine when you first ever felt these feelings. I felt it when I was very young, when I was talking to a girl about puberty, and I felt sad, and cheated, that I would have to become a woman and no longer be "one of the guys". You must understand that I was one of those rough and tumble tomboys as a child, I grew in the country, I wore my brothers' hand-me-downs, I was always playing basketball and getting into mischief, I had a short utilitarian haircut. Gender just wasn't acknowledged in my friend group, sex was immutable, of course, but we were all people first and foremost, and it was deeply distressing to imagine that I would suddenly be treated differently just on basis of the sex which I had no control over. Later, as puberty hit and sex segregation became more prevalent in social groups, when I lost nearly all of my male childhood friends for reasons I could not understand, I was exposed to extreme social pressures to shave, to stifle my personality and my naturally loud voice, to grow out my hair, to wear weird clothing, or else be viciously verbally and physically bullied by teenage girls (arguably the most cruel subspecies of man). This, coupled with exposure to very conservative religuous family members who also demanded I perform this bizarre, soul-crushing version of womanhood, made me feel as though I had no sense of personhood, no agency, no escape, and that I was nothing but a doll for everybody around me. I longed to be a man, and I hated everything associated with femininity, including my body that was changed by puberty, because I saw it (subconsciously) as evidence of my own subjugation and lack of personhood. Being male represented an escape, it represented freedom, because all of the traits I was routinely punished every single day for, were praised in men. I envied the mechanical advantages they had, skeletally and muscularly, in sports and scraps.
Abandoning escapism and transgenderism sucked, but when I examined my history and acknowledged that there is nothing wrong with my body, that I was merely facing the trauma that comes with being an autistic, gender non-conforming female, in a society that demands extreme gender conformity at the expense of self-expression, I saw a way out of this mental illness.
I am certain that something similar happened to you, and if you are on here, you are probably autistic too. With aspies, what is treated as normal social conditioning can feel deeply traumatic, I suspect that this is the reason why there is such a high comorbidity between nonfunctional autism and issues concerning gender identity.