How do I overcome my appearance disorder?

In the third year of high school, I couldn't concentrate because of my appearance, so I spent most of the day watching YouTube videos about plastic surgery and crying while looking in the mirror and making a fuss until I failed. I also had to wear a mask at the academy alone and go ask the teacher questions because of my appearance, but I couldn't do it even once because of my appearance. I couldn't concentrate because it felt like the boys were laughing at me. Even now that I'm a third-year student, it's so hard. Even when I'm solving a math problem, I look in the mirror and say I want to shave off 2 centimeters from my chin... I just cry when I look at my side profile. I was pretty in middle school, but I was a good student back then. I was always in the top 10 in the entire school. But when my chin grew out in high school, my life was ruined. My parents wouldn't let me get braces, so I need to save up 1,500 to get double jaw surgery and start a new life, and I'm thinking about taking out a loan...