The most important part is that you are still you - kind, generous, good. Those things don't change, you are still your weird and geeky self - all that (*all*, as if..), transgender means is that you have insight into yourself in ways that others don't, because you've become aware of aspects of your gender do not fit into the way that you are treated, behave, or desire to appear, (and it may only be one aspect that triggers your anxiety).
This is our journey of understanding ourselves, and how we relate to the world (and how it relates to us), physically, socially and mentally. Understanding ourselves means we can relate, compensate, adjust and improve those aspects, because we are aware, and not blindly stumbling on.
Quite often we find out simply through the comments of others (in my case, I was always such a girl), or an irrepressible need to get out of the gender uniforms that we socially are expected to have, or a deep seated desire to be rid of physical characteristics that are used as gender markers, it may however be subtle, in our awareness of our social interaction, knowing that we're doing it wrong, worrying, making mistakes, and then questions, questions, questions of why- with the anxiety and paranoia that accompanies them.
MichelleP often tells of when she was interviewing a transgender lady, the though that crossed her mind was 'she's so brave' - and the initial blind panic that ensued. Dena can talk all about how it was her social environment that didn't tie up, as just a start and we are all still here, as terrifying as it may seem now, you can get through this, and it doesn't mean that you suddenly start dressing as a man, or need surgery, or hormones, and doing any of those are choices that you may make, and you may choose to make them, because you feel better about yourself when you present that way, that is all.
It's going to take time hon. Honestly, I've suspected my gender as a cause of many of my issues for a couple of years (how can one so bright, be so dumb;) ), and the world hammered the message home 18 months or so. I'm now dealing with my own anxiety, and panic, with the help of.... a therapist, and medications - I have a lot of unknowns, apart from one, and that is the unwavering support of folk here who will help, suggest, support, love, offer kindness unconditionally, regardless of our personal circumstances.
There is hope, as the many successful stories here are testament to, and yes you will be able to find your own path, to being a more authentic you, where you are comfortable with yourself.
(Hugs) - it's going to be ok.
Rowan.