@Ai-chan_loves_unnie
Some trans people do regret their decision to transition, but the figures on that shows it to be an absolutely miniscule amount. Iirc, the rate of detransitioning is around 1% or so, and of that 1%, the majority of that is people who detransition not because they realized they weren't actually trans and regret transitioning, but because they feel they can't transition at that time or at all (such as for financial or social reasons) but are still trans. If someone does realize they weren't actually trans, then good on them for figuring themselves out better, and hopefully they can live the life they want to live.
@Aidhm
For one, those statistics use suicide attempt rates as you can't really ask a person who killed themself "hey, you trans?" or "hey, why'd you die" and therefore any data on that subject won't be accurate. And those statistics are generally taken as either just pre-transition or as at any point in a trans person's life. It is definitely true that the suicide attempt rate for trans people is insanely high pre-transition, but that is not because of being trans or regret. Secondly, the two things known to reduce suicide attempt rates, depression, anxiety, and the like in trans people is transitioning and social acceptance as the gender they say they are (which is social transitioning which is also part of transitioning, so really just one thing). Post transition, the suicide attempt rates drop down to nearly the cis average. And that is one of the more extensively studied things relating to trans people. The fact that the suicide attempt rate is so high is pretty appalling, but not appalling in the sense that it would suggest trans people are regretting being trans so much and in such high numbers that they kill themselves, but actually appalling in how it reflects how poor society is at helping and supporting trans people. Please don't bring up transgender suicide statistics if you are going to use it justify transphobia.