I've had BDD pretty much my entire life. I literally hate my face. I don't understand how I can look so ugly and just 'wrong' compared to everyone else. I mask it pretty well in my daily life but inside it's all-consuming and exhausting.
BDD is brutal on the mind. It can downright, be taxing, leaving one mentally exhausted. Do you have anyone in your life who gives you a positive narrative? Are you trying out therapy? Both are great for combating the negative narrative that's on repeat.
@Justwanttobeloved is right. Someone lied to you so many times that now it has become your truth - brainwashing. They taught you to hate yourself, see yourself as ugly and wrong. It was cruel abuse. Break that cycle by realizing their cruelty is no longer your reality.