Throwaways represent!
This is pretty much how I am, but a little weirder. SEXUALLY, I want to be a girl and I think I always have. All of my fantasies ever since I was a child involve me imagining myself as a natural female on the receiving end. But I don't want to become one, I just wish I was born one. Not only that, but this really only extends, for the most part, to sexual fantasies. I'm not sure I'd rather be a girl in day to day life. When it comes to the long-run, imagining myself in my upper middle ages and beyond, I'd most definitely rather be a man. I'm also straight and capable of having a healthy straight sex life.
I also adhere to my gender in all of my online accounts, except for when I create them for the sole purpose of being a "woman" and getting off on it. I'm not proud of it and I don't do it anymore, but I've definitely RP'd with many men pretending to be a woman and I'd get off on it. I would convince them I was the real deal, and quite often just delete all my shit with no notice once I felt shitty enough about it.
Sexuality is a weird thing.