I don’t know how to love myself

I hate the way I look and it stresses me out so much because so many people are always calling me pretty and beautiful and my mom is always saying how i should always love myself and I don’t but I don’t want to tell her that because I feel like she would be disappointed and give me the wrong kind of encouragement that I need. I always find a way to hate a part of me and I struggle in health class at school when they say to write down things you like about yourself and I can barely write three. I don’t know what to do or who to go to, I feel like I’m trapped in the bubble of loneliness and sadness and there’s no way out, the worst part is I’m only in middle school and I feel like I’m too young for all of this emotion and hate for myself, if anyone has any tips plz share them.