There are many similarities between my metabolism and yours. When I was young, I had frequent bouts of tachycardia and a possible heart murmur. Because I am a bit older than you, my GP decided this was just something that happened to some children and they would go away with age, so it was never addressed. Ultimately it did disappear.
Like you puberty onset was relatively late for me though not as delayed as it was for you. It did not begin until about age 14 or 15. By then most of my male peers were talking about their sexuality in ways I did not understand. I ended up being somewhat tall, though not your size. I ended at 6‘2“ in college. Like you I was a string bean and weighed about 150 pounds. I had an ectomorphic body type and somewhat androgynous appearance, though not particularly effeminate.
When I took my first position out of law school with a federal agency in Washington DC, I frequently suffered from bouts of extreme exhaustion early in the afternoon. I went to an internist who tested my thyroid and blood sugar levels to see if I was hypothyroid or had low blood sugar or abnormal glucose tolerance. He never found anything of significance and nothing was ever done.
The answer to the puzzle did not begin to appear until I was treated for BPH with finasteride. To say I reacted badly would be an understatement. Among the 20 health problems I suffered, one was a total loss of sexual function. Initially after repeated prodding of my urologist, he prescribed amantadine off label because he suspected my dopamine levels were low. It had no effect on me physically except to make me very lightheaded and create difficulty with balance. It was so awful that I had to stop it after about a week. It did not solve anything and created severe side effects. This then led him to test my testosterone and estrodial levels. At this point I had been off finasteride for over a year and a half so its residual effects should’ve been eliminated. We discovered that my testosterone was 100, significantly below the normal male minimum of 300, and my estradiol was 122, in the low normal female range. These hormones had probably been like this for a long time pre-dating my unpleasant experience with the finasteride. At this point some limited genetic testing was done. It was discovered that my AR gene was female, being longer than that of normal males, and relatively inefficient in processing testosterone. It explains a lot. And probably also is the reason why I had suffered extreme gynecomastia on Finasteride. I had grown breasts which were larger than many of my cis women friends and they were envious, though my male friends were horrified. My somewhat female physiology also probably explained why amantadine was ineffective on me. My endocrine system regulated the reuptake of dopamine poorly. Pushing its production did nothing to correct the issue, but did create secondary problems.
As I read your article, I saw many similarities between your Health history and mine. Obviously they are not identical, but that leads me to wonder whether some of the underlying physiological differences between trans women and cis males are expressed in particular ways among our population. There is clearly something going on here.
As a sidenote, the function and development of the AR gene (which regulates the response to testosterone) is on the X chromosome regardless of whether someone is XY or XX. Yet another subtle indicator dictating against the broad assumption of the gender critical crowd that sex and physiology is binary and strictly a matter of which set of chromosomes you have. The picture is far more complex in reality.