Just a thought - can't speak from experience as I've never had a baby of my own. I'm wondering if it might be helpful for you to talk to your doctor or to a nutritionist/etc about an appropriate diet if you are currently breastfeeding. If you are, your body's nutritional needs might be different than they would be otherwise. I would particularly caution against doing anything too extreme whether or not you are breastfeeding - you need to be sure that you have the energy and health you need to look after your family.
If your husband is worth his salt, he'll get it, and you'll be just as beautiful or more caring for the life you've made together than you were before. It's awesome and praiseworthy to want to stay attractive to him, but do talk to him about it, and give yourself time. :)