I went through the same thing throughout my early teenage years. People can be so cruel & hurtful. A true friend would never hurt you like that. Never be ashamed or embarrassed about your looks. I am certain you are a wonderful person and I know you’ve heard it before but beauty is not about looks it comes from the heart. Concentrate on being the best version of yourself and you WILL be beautiful to those who appreciate & deserve your friendship. Good luck to you.