You've gotten all the good advice already, but I just HAVE to echo the sentiment.. don't feel BAD for putting the baby's needs above your want to lose weight. You are doing the baby the BEST favor you can by nursing, and also by being conscious of your own health. As was already said, just get your energy from good food and avoid the "white stuff" and you can ease into it as you go.

BTW, both of mine went through the "always hungry" stage, and it doesn't take long for your body to adjust to the demandm but take care of yourself and get some rest. Adequate water intake is vital as well.

Good luck!