I think you might consider figuring out how to lock up YOUR OWN FOOD where she has no access to it.....obviously it's NOT her home since you are paying rent also & you are JUST roommates.

You seriously NEED to learn how to stick up for yourself because it seems your only way to feel any sort of control is through your restriction of food. Just because you are non-confrontational doesn't mean you can't learn how to stick up for yourself in a non-confrontational way. ED's always have some serious underlying issues of feeling out of control in other areas of one's life.....& you could really use some therapy to learn how to handle your life better. I know for me, DBT was one of the best therapies to learn skills for handling emotions, depression, & interpersonal relationships along with mindfulness so that you are seeing what is really going on IN THE MOMENT in your life & understanding it better.

I know when my life gets totally out of control, I always fall back on controlling what I don't eat.....ED's aren't just about body image....there are ALWAYS much deeper issues going on that haven't been handled & until they are....the ED is always going to hang around to haunt.