My life was destroyed by myself

When I was 14, my classmate Lisa asked me to accompany with her to go on a diet. I refused at first but I accepted finally due to her constant begging . Then, I lose weight quickly and was diagnosed with anorexia. There wasn't doctor know how to treat eating disorders so I did't receive professional treatment which made me suffer from eatinh disorders for nearly ten years. I was diagnosed with liver tumors recently and doctor did not know wether my tumots are benign or not so I need to do interval checking for moniyoring my tumors. I am the only child and I am feeling guilty to my parents bc of my illness. My classmate Lisa doesn't admit that she ask me to go on a diet with her after knowing that I suffer from anorexia. I hate her and even want to kill her!