You seem pretty confused between the concepts of gender identity and sexual orientation. Most trans people don't talk about their gender identity in terms of who they want to have sex with or who they're attracted to.
Nor does a transgender identity have to include sexuality. Identifying his transgender rarely involves a change of sexual attraction. Transgender women who were attracted to women usually continue being attracted to women, and those who are attracted to men usually continue being attracted to men.
It works that way with transgender men too.
Also, homophobic much? Did you know that child development experts say that most young adolescent boys sexually experiment with other boys, and that that's an ordinary and fairly healthy thing for most people — and that it doesn't reflect eventual adult sexual orientation?
You seem to take the position that such an experience would have traumatized you, and you seem to do so in pretty homophobic terms. As if same-gender sex were so fraught it must be damaging except in exactly the right circumstances.
In reality, if you'd had a homosexual experience when you were an early adolescent, you most likely would have reacted like most straight teens do in similar circumstances – i.e. processed it and moved on as you matured. Sexual experiences can't make people gay any more than they make people straight.
Sexual orientation doesn't work that way. Neither does gender identity. The parallel you're trying to draw says little to nothing about the situation, because you don't understand gender identity, probably because you've never spent any time with transgender people.
If you did, you'd realize your early adolescent experiences aren't connected to how trans people experience gender.