Advice

I am going to lay it all out so I met this girl online almost four years ago but when we met I was using pictures of my cousin because well he's everything I want to be. I finally told her the truth back in April and we were trying to stay friends well she finally cut all ties with me telling me she would never forgive me she hated me. I know I deserve it but I am so miserable without her can I get some advice on how to stop mentally killing myself over this.