Okay, so I was kind of confronted by someone I know very well and I haven't come out to them. They asked me something along the lines of "what the [opposite of heaven] is wrong with you?! Are you gay or want to be a woman or something?" I panicked, and I known I looked like I was panicking. I ended up ignoring that part of the conversation and just kept going with the conversation we were talking about before that. I kind of hate myself for not saying something like "so what if I was a woman?" but it came from left field and I'm not one for confrontation... I know I'm going to have to revisit this in a few weeks. I am so trying not to hate myself.

Don't hate yourself... Like you said, "It came out of left field" and yes you most likely will have to revisit it sooner or later. While I can't say what the outcome will be, if it a true friend, most likely they may understand. Hard to say... Just try to keep your head up and take things as they come.

We all have these moments so do not hate yourself. It doesn't sound like you could have given a good answer. I personally think you handled it well. I think a response would have inflamed this person and led to something bad. 

Yeah it sucks when you start showing and the reactions start happening. I'm about there too and my inate reaction would have been the same. Clam up and change the subject.

It's something you're going to have to face, esp. if you're going all the way to full-time. You might want to start working on your "coming out explanation" speech and rehearse it so that you can spit it out when confronted.  You'll probably have to give it several times ("No, I'm not gay, I'm transgendered, blah blah blah", "No, I'm not gay, I'm transgendered, blah blah blah", "No, I'm not gay, I'm transgendered, blah blah blah" etc etc etc)

It would have taken a superhuman ammount of confidence to have had the answer at hand sincew you weren't expecting it. Now you must get into the mindset that you can expect it from at least a few people. As noted above. Practice, so that you can be calm in your response. Good Luck.

Yeah, I guess I need to meditate more on this. I'm still confused, mostly because I've known this person for a while and it just shook me up.

They may have just realized the difference and because they were familiar with you they didn't have the filter to either not say anything or phrase it in a more tactful (or indirect) way, which... might have been more "dangerous" if it didn't raise your guard and you inadvertently outed yourself.