I have been there and still hope to publish something one day. I started writing two non-fiction works, but never finished. Damn my laziness.
At the end of the day, you really want to write something that will stand out in some way. To get a publishers attention you really want to show that your work is marketable, eye grabbing, unique, profitable or all of those combined. While there is a lot of garbage that's published, there is a lot of great work that ends in the trash bin. I think an autobiography of a transgender person is interesting and could be picked up. However, keep in mind that this kind of a book would need to provide painful and personal details. If you want people to learn about your journey, you will have to share some really important aspects about your life. The best writer is one who discloses and bares all (in my opinion). You need to show why the reader should care about you and your plight. For a book like this to work, there needs to be uncomfortable intimate details. Otherwise, it's a general biography that you could read anywhere about anyone. Now you can do this sort of a book without disclosing your name, but in this day and age people are able to take obscure info together and pain a picture. Therefore, it might be hard to keep your privacy while doing such a detailed work. Maybe not, but realize nothing is ever certain and you will be taking a risk by publishing your story (even under another name).