Thank you very much for writing this informative essay, Julia. Your observations and analyses are of value for both the transgender and cisgender communities.
I agree that the term transgender can only serve as an umbrella term, albeit with the risk of causing a lot of confusion especially in the cisgender community. I am transsexual and while I use the term transgender most of the time for ease of conversation, I prefer to identify myself as transsexual or female.
Also, I was late in my transition for the same reason you shared. My state of dysphoria during puberty was very intense and caused me to build very strong defenses that took 16 years to dismantle. I understand.