I think it's important to look good to YOURSELF because that will help your confidence level and be one less thing to worry about. I think looks is the easiest thing to work on so it's a great place to start. Pay attention to posture - when I finally started standing up tall, people approached me way more often. Since you have PTSD, then having some control over one aspect of your life is probably comforting in a way. ED's are often fulfilling a need to have control over a life that feels out of control. However my guess is it makes you feel like crap most of the time because you are hurting yourself nutritionally. If you are into the binge/purge cycle then it's also guilt causing, which further hurts your self esteem (at least it did for me). You are probably throwing your whole body off kilter, affecting your blood sugar and thyroid levels and causing low moods, anxiety, low energy etc etc. I certainly empathize with your problems. I have experienced much of what you have described.

I can see why this thread was tagged as 'borderline personality' at one point (also sometimes referred to as complex PTSD). Although you may not have that overall problem, you have some of the symptoms so you may benefit from the treatments that are offered for that condition (I believe most people with self-esteem issues have borderline traits, some have more and to a bigger extent than others). And no, I am by NO MEANS labelling you as such and I recommend you NOT label yourself either. I simply encourage you to read up on some of the causes, symptoms and treatments as they may be helpful to you. They focus on changing beliefs, negative thoughts, and dysfunctional behaviours and relationship patterns, many of which may have become ingrained over a lifetime. You may also want to read "What to say when you talk to Yourself", a book by Shad Helmstetter. If you could apply his concepts, I think it would be life changing. It's mostly about turning that self-talk inside your head from negative to positive.

I believe you have already identified your basic problem (insecurity and low self-esteem). Whether you are beautiful, ugly or average, these things are so very minor compared to how you feel about yourself, your worth, your identity, your personality, the very core of your being. I wish you the very best in tackling the problems 'beneath the mask'.