I feel much this way too, though maybe a bit differently. Weight is very tied in with my self-worth. I tend to strongly associate negative feelings about myself with 'feeling fat'--a specific feeling I developed quite young. As long as I felt fat my life couldn't be enjoyed. A lot of those feelings actually did pass when I lost some weight, but it would definitely become a major problem again if I ever gained a lot. If I imagine myself becoming obese in the future I just imagine my life as being so worthless. But that's obviously quite stupid because thinness doesn't dictate value.
I have a similar problem. It's not because I want to disappear, but because I want control. With all the shenanigans going on with my husband, I haven't been eating. I know it's a problem, I know I'm desperately close to dipping back into anorexia, but there's this nagging voice in my head that if I give in to the hunger, I've given up control.
Oh, something else I maybe should have added. I have a long, messy, miserable history with eating disorders, which almost killed me on a number of occsasions. My emotional dieting is almost definitely related to my history, and although I'm technically recovered, it is something I battle daily.
However, this doesn't mean that you have an eating disorder, although it's something you should maybe consider.