It's nobody's fault you have a stutter. Many people, myself included, believe it *is* hereditary but like all bad genes passed down, it's just bad luck and nobody can predict it. As for not having the courage to talk to girls, get out there and meet somebody. My stammer is quite severe and I'm not exactly a catch yet have rarely been single since turning ~13. As long as you can come out of your shell, you'll be fine. Relax and don't worry about what they think just focus on having a good time and they will too