In all honesty, the claim that you "felt like a girl" makes no sense. What does that mean, exactly? That you liked dolls and tea-parties? That you were interested in fashion? That you didn't care about sports? Those are just stereotypes and roles defined by society. The truth is, there is no such thing as "feeling like" a girl or boy. A girl's mind trapped in a boy's body is a specious notion because in reality, gender has nothing to do with feelings, opinions, attitudes and personality. Those things are individual, not gender-based. You changed your body because you too believed what society told you was true: you too believe in false predeterminations of female and male behavior and personality.