I also use weight as a way to make myself less attractive, and attract less attention. I would really like to lose weight just to be healthy again, but seem to self sabotage. I also have issues with skin picking, with I also think is to make myself less attractive. Because I have always had bigger boobs anyway, I feel like they become more noticeable when I'm skinny and attract unwanted attention.
Another part of it is that I have a tendency to engage in impulsive, risky behaviours/unsafe sex etc...and I think I use being overweight/covered in unsightly sores as something to stop me doing things like that, because the embarrassment of how my body looks is the only thing that is strong enough to stop me doing the impulsive/risky behaviours. It makes me feel uncomfortable to have men attracted to me because I don't know how to stop myself responding.
It's hard, I wish I had some answers, but I don't really. I'm just trying to take it easy on myself and hopefully by talking about some of this stuff, at least online, I can get past it slowly.