Bulimia after break up :(?

My ex left me a month ago in the end of our relationship he started being secretive about girls he would talk to and get defensive when I would ask who they were. They were all so beautiful. I start eating and throwing up little by little now I do it after everything I eat. Im in therapy but I feel like its controlling my life! I miss my ex he left and never talked to me again I feel so worthless he was so handsome. How do I build my self esteem?