No one posts too much we all post as much as we feel we need to.
I think just about every transgender person doubts themselves at one time or another, especially early on in there discovery. I know I often thought to myself "i must be making this up transgender is so rare what are the odds i am really trans" or something similar to your thoughts of just trying to be special or weird, even today there are parts of my life like my intrest in wicca/paganism that I worry are just me trying to be special. But when these feelings continue for years on end its not just confusion, there is something there. It may help just exploring this side of you even if you discover that transision is not needed or wanted if you enjoy the expriance that's enough.
I think you should take your grandmother up on seeing a therapist. A therapist especially one with transgender experiance can help you discover your inner truth and be a sounding board that you can trust is not telling you what you want to hear.
::hugs:: your not alone in the stress and depression I think everyone here has at one time or another dealt with those hurdles. I know I deal with them all the time, but we all deal with it, we can deal with it sometimes it just takes some friends and somewhere to vent and susans place is very good for both.
Serena