I've known several sex-change victims - which is what they really are.
They have severe mental problems that predate their "operation". Like the unbalanced vain woman who believes that all her social and emotional problems will be solved if she just gets that facelift or breast enhancement, they believe that they will suddenly become sane and happy if they "just" mutilate themselves.
When it doesn't work, they are filled with regret, but as you say it's too late and they can't go back.
Johns Hopkins quit doing "sex reassignment surgery" years ago when they discovered that many of their patients committed suicide. In my opinion it's medical malpractice to participate in this.
It’s called “body dysmorphia” and it is a mental illness. Michael Jackson suffered from it. So do anorexics. And so do these “transgendered.”
Surgical eunuchs have always been around.