First heartbreak
When you have a crush on someone in high school, it usually is the first time that you really fall for someone. Up until that point, you were probably just playing sports or focusing on arts and crafts in elementary school, but now, everything is different. So it can hurt a lot when that crush doesn’t work out.
In this situation, this girl really liked her best friend, but because of pressure from other people at the school, he said some mean things about her. He basically called her fat and said that she had no chance with him, which could really hurt someone’s self-esteem. It’s already fragile at that age.