Why are you afraid? Are you intimidated by what others may think or are you yourself just new and not comfortable to the idea? I personally don't find anything wrong with being gay and identifying as a girl--I've got a female friend who I just recently discovered has the exact inverse of your label. She's female and ultimately likes girls, but feels she identifies as a man. I think you should live as whatever you want to be, especially if it would be more painful for you to cover up your true self. You'll be okay!(*hug*)
If you feel you're a woman and you know you are, then no doubt about it- you are. Your gender is not dependent on what's in your pants- it's how you feel and how you identify. It has nothing to do with your sexual orientation (there are plenty of transwomen who identify as lesbian, bisexual, asexual, or any other label on the sexuality spectrum). If you are a woman then it's your job to own it and accept it. There's absolutley nothing wrong with being trans*- or being a woman for that matter (Odd as that may seem coming from me...) I'll be here if you need any more advice.
I think the only trouble with that is gay female implies lesbian I'm not saying there's anything wrong with it, and if that's how you most comfortable then go for it. There's nothing to say you shouldn't, just be carefull who you say it too, some people will take offense to it
