Hm, you've said a lot, so there is a lot to cover. I've been very busy traveling and haven't been able to respond to comments like this, so apologies for the delay, the reasons for the delay were on my end.

First, I am hearing you disclose that you are struggling mentally, but it's a bit ambiguous what you are struggling with. I hear you saying that you are sensitive to feeling criticized or attacked, and sensitive to having disgust or stigma as a reaction to your mental illness.

One aspect of the whole debate about whether gender dysphoria is a mental illness does have to do with exactly that stigma associated with mental illness, and a reason for that is that homosexuality was also stigmatized and classified as a mental illness. As gay rights were achieved, the stigma and classification of homosexuality as a mental illness was reconsidered.

I would like to hold space for both realities: that classifying something as a mental illness is a way society communicates stigmatized way of thinking about behavior, and also that this stigma can be an inappropriate response to mental illness (even classically stigmatizing mental illnesses, like psychosis).

It is also worth noting that I did notice you said you were in favor of gender affirming care as a treatment of gender dysphoria, even while still thinking of gender dysphoria as a mental illness. To turn this around a little, I wonder if you noticed that I admitted gender dysphoria could be thought of as a mental illness in some sense of what it means to be a mental illness.

I do think you might have missed some of my larger points, which were not primarily trying to convince you that gender affirming care is important or the right way to treat it (which you have already affirmed), but why that is true - this gets to the point about classifying it as a mental illness.

Gender dysphoria is a genetic, hormonal, neural, and physical condition that causes both physical and mental symptoms. It is not just a mental illness because it is also a hormonal disorder, for example. It is more like diabetes or hypothyroidism. You also experience mental symptoms if you are an untreated diabetic, for example. The brain develops a certain way, and the body develops another way, and as a result the dominance of the wrong sex hormones creates problems. As Ada has already pointed out, this is true for a cis person - if you take a cis person and raise them as the opposite sex, they experience the same gender dysphoria.

"Mental illness" is very broad and that gets into problems, though. Some mental illnesses are like gender dysphoria, caused by genetic and physical conditions which can be alleviated medically through various drugs, surgeries, etc. Sometimes the brain just doesn't work for some reason that ends up being more physiology than psychology.

Other mental illnesses are caused by the experiences we have and our psychology. I suffered from an eating disorder at one point as a result of abuse from a family member. I have experienced hyper-vigilance and symptoms of PTSD as a result of abuse as well. Both of those were not caused nor solved through medicine or surgery, the problems were more psychological.

So what is so important about classifying gender dysphoria as a mental illness? Usually this comes up when conservatives wish to dismiss gender dysphoria as a legitimate or valid reason for someone's gender identity to be respected. It's a reason for them to not just stigmatize but dismiss - the conservative might argue it's a mental illness like PTSD (and not a medical condition like diabetes). They then want to argue that social and medical transition is inappropriate and heavy-handed as a treatment, and instead it should be treated with talk therapy (which is conversion therapy), and so on. This is based on nothing more than discomfort and bias about trans people, there is no evidence supporting it (and plenty of evidence for why we shouldn't treat gender dysphoria with conversion therapy - like, it doubles the risk of suicide).

I understand completely that this conservative "argument" is not what you are agreeing with, but you should know that the only reason we are having this discussion is because gender dysphoria has been framed this way by an anti-trans movement that aims to deny trans people their medical care. It's a needless discussion and way to rationalize and wedge people on the trans topic - doctors are not wringing their hands over this or wondering whether it's a mental illness. The doctors and scientists know now that gender identity is biological and genetic, that gender dysphoria is not like PTSD or other mental illnesses like that, and that the treatment is social transition, hormones, and surgeries as appropriate (i.e. as the patient seems to need it, based on the consensus of the patient, their therapist, and doctors).

So why is this so relevant? What does it mean to be a mental illness to you, and why is it so important to determine if it is a mental illness or not?

EDIT: I forgot to mention, one of the problems with thinking of gender dysphoria as just a mental illness is that this is often used to imply the experience of gender identity is delusional when it's not according with the assigned sex at birth. A neurobiologist might argue that the brain is where a person's identity exists in the first place, and if you were to choose between someone being their brain or their body, it is obvious people's identities are in their brains. To this extent, trans women are women because their brains are female - their gender identity is biologically hard-wired, and not a delusion, and thus not a mental illness. The body is what is wrong, so it's what gets changed.

EDIT2: oops, I didn't forget to mention that, it was the first point I made in my initial reply to your comment 😅 We're going in circles now!