Have you met with a nutritionist? If not, I would URGE you to do that with someone familiar w/ the band. Most of us are given guidelines of what to eat. Just eating healthy is not good advice, in my opinion. You need sample menus, guidelines, etc. For example, my NUT and dr. have me on 1200 calories per day and 60-70 grams of Protein. If I do not get in the proper protein, I am hungry. Eating solid Proteins, followed by fruit/veggies will help keep you satiated and help you lose.
You are not a failure, it just sounds like you need direction. Also, make sure you aren't taking in too many liquid calories. Those won't do much for you and no more than 1 Protein shake per day.