I have battled this off and on for 20 years, and have seen other friends go through it too.
I watched one cut her arm up and would only stop once she had cut herself so badly that she had to go to get stitches. It was the only way that she could feel anything.
It is a scary, lonely, and a disease that is the only thing that you can control when your world feels out of control. It often has little to do with being or feeling fat.

There are some amazing websites out there, and there is a lot of support for friends and caregivers. Please don't ignore them, or not say anything.