Thanks for sharing your story. Mine is kind of the opposite; while I also began my gender transition in middle age, I changed my IDs to the "M" marker and later pondered whether I should get an "X" instead. But ultimately, I decided that having that letter on my state ID or passport will not confirm to our still-very-binary society that I'm non-binary.

https://funcrunch.medium.com/traveling-while-trans-does-x-mark-the-spot-1a5beb48d107