Anyone else might have said something as hurtful, but coming from your brother, those words have a greater impact.

Reactions from my own family. Both my son and daughter=-in-law know about 'me.' I won't be transitioning ever, but my daughter-in-law still asked me which pronouns she should use. My wife told me she loved me, and wanted to tell my son; neither of us knowing he had known for a few years. (An open Word Document on a family desktop can make for great fiction fodder, BTW)

BUT

I was out grocery shopping with my younger brother last summer. He knows nothing about 'me." Walking past a newspaper display,he began to rail against immigrants and such, which would have been harsh enough; especiall since our father was from Sicily. But he Mega-MAGAed the tirade by sayin how wrobng it was that poeople were convincing kids to 'change their sex!' It devolved from there.

As much as I have endured in my lifetime, his words were about as hurtful as anything I evere heard. Because he's my brother! Not a pundit. Not a preacher. The kid who played with model cars and rode bikes with me. It HURTS because neither my brother nor yours is questioning an opinion. They are questioning our essence. WHO we are.

I am so very sad for your blog; especially when I realize you and I aren't alone in this, but share a commonality with our friends and family on this site. Commonality can be freeing, but in this case it is horrible.

All my love!

Dorothy, your brother is an MD? Maybe has a degree in the field of Genetics? My GOD! I want to meet him. I've been researching transgender for more than forty years. What I have learned is most have it wrong. The "experts" are experts only in their own mind and their loyal subjects. Love, even medical doctors have most of it wrong.
You must love the intelligence factor everyone claims as it seems everyone has an expert opinion. The best expert advice comes from the least qualified to be giving it. The most truthful data is the following. "Don't quote us because we aren't sure what we mean."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8799808/
As a library, NLM provides access to scientific literature. Inclusion in an NLM database does not imply endorsement of, or agreement with, the contents by NLM or the National Institutes of Health.

I've had two private physicians tell me to not darken their door. I had one Doc at the VA who would be in total agreement with your brother. She could no longer support me as trans because I aged out of transgender. My relatives, brother, and sister won't talk to me. That's okay, they hated me anyway. My son won't talk to me. He has his signals mixed up in religion. He won't talk to his sister. She's an exceptionally beautiful woman. I might be a little prejudice. She had M stamped on her birth certificate.

Dorothy, you were brave enough to cross that great divide. Live your life and enjoy the comfort and fun things that came after you took that step. It's the best statement and possible sweetest revenge in life to annoy the hell out of one's detractors when you accept yourself as this is God's Gift. I come across so many girls who want to please everyone else and they fail to embrace who they are themselves.

PM me, I'll give you my phone number so you may give it to your brother. I have been looking for the all knowing messiah, who can enlighten me on the do's and don't of everything transgender.
Love you Dorothy, accept yourself, live your life.
Barb
Life is a gift meant to be lived, not worn until it's worn out.

Rather than facts. Often the emotion is fear because what you are doing is undermining his masculine superiority. We know that to be a delusion and it is only a factor in paternally governed societies, which rule on the dominance of males through physical force, through which they hold most budgets. It is all an illusion because a male society needs women, they can't breed without us. So if you can try to forget his opinion as both uninformed and unhelpful ( and hide his viagra).