Oh my. I know how hard that is. Thankfully, I've never had to go through this, but my best friend has had to go through it several times with two different friends. It drove her to her own breaking point. With both, she eventually realized that they were repeatedly emotionally hurting her (and manipulating her) to a point she couldn't justify and so she distanced herself from them. It tore her apart to do so.
I hope that doesn't happen to you, and that your friend will be okay. Sadly, food will not make the pain of this any better. Breaking your diet, making yourself less healthy, will not make it all okay again. I hope coming here has helped you with what you are going through. And please, don't hesitate to use any support structures you have. Churches and schools are both good resources for support.
I don't pray, I'm sorry. But I am shedding a tear for you. And giving you an e-hug.