Please don't blame yourself. The majority of breast cancer has no discernible cause. That can be scary too, as it means there is little way to avoid it. A healthy lifestyle is good, but I try to pursue it just because it feels right in the present. No one's habits are perfect. If I might make a suggestion--try and give up looking for a cause and blaming yourself. Can you try to go forward appreciating yourself and the care you are getting? Sometimes when I'm very down on myself I try to treat myself the way I would a friend or my daughter--I would't be mean! How are you doing physically? What helps you in terms of support?