You should certainly tell your boyfriend how you feel, but I'd wait to tell the family. As the relationship with your boyfriend has lasted so long, hopefully he'll accept it. The first thing you need to do is to try dressing as a male and going into public. This is what a doctor will tell you to do before starting hormones, and then surgery.
The idea that the hobbies you have fit a gay man more than a straight women is ridiculous. Please stop wrapping your mind around stereotypes so much. I'm a girl, and I play video games, build computers, and enjoy using power tools. Does this make me a transexual? No.