People have doubts all the time, so it's not uncommon. Personally, I have never had doubts, but I have questioned whether I could ever pass or if I could successfully transition. Still, I know plenty of women who weren't 100 percent about their identity. In this case, I would suggest going to therapy before making any decisions. You don't want to do something if you aren't sure it is right for you. I think it is good idea for you to learn more about yourself before taking action.