Thank you for sharing your experience. It breaks my heart to see young people sucked into the trans black hole by sophists whose motivations are largely political gain or feeling batter about their own bad decisions. It's good to hear that you were advised by someone without those ulterior motives.

As for preventing people from making such a terrible decision I think that your experience was exactly right: young people questioning their (gender) identity should be gently reminded that sex is an immutable biological trait and that feelings of body dysmorphia (especially around puberty) are not uncommon and nearly always pass with time.