on diet plans

Ok, I admit ... I am 15 lbs overweight. After four months of giving birth, I am still struggling to get my pre-preggy weight back. I thought shedding off few pounds would be easy since I breastfeed my baby, and with so many late nights taking care of an infant ... I thought I can lose all those unwanted fats fast. But boy, I was wrong! I am still looking for fad diets that work. I've tied after six meal, south beach diet, all fiber crash meal and all-soup diets, but unfortunately, nothing works for me. Well, I am bad with being consistent with my diet plans. Hence, I am a big failure in shedding off those fats. Think instead of concentrating on different diet schemes, perhaps I need to enhance my discipline and will-power first before I launch on successful diet plans. What do you think?