I don't know much about issues that transgender people face, so I apologise if I come across as ignorant.
From what I understand, it sounds like you are really struggling with fitting in and knowing, I guess, who you are. Is that right?
I don't feel like I can speak on gender troubles, but I do have what could be a similar issue but relating to culture. See, I'm ethnic Chinese born in Australia, and I grew up in a very western environment with almost no Chinese friends. Anyway, my point is I struggle with my identity and I don't really know whether to call myself Chinese, or white Australian (which I'm obviously not), because even though I am 100% ethnically Chinese, I feel like I identify more with a western culture. Yet, I don't fit in either and I do lie kind of in the middle...which would be fine, except that my brain tends to want one or the other, and people seem to expect one or the other.
So a long story short, I do understand that identity issues are really tough and if you don't feel like there is a middle, I can imagine that makes things really hard for you. I am curious though why you don't feel like there is a middle ground?