I always read and followed the advice that you should never TRY to lose weight while breastfeeding. Yes, that sounds like way too few calories! I think I was up to like 2,200 calories when bf'ing! And I still lost weight (again, I wasn't trying, that is just how my body reacted to bf'ing, I dropped weight).
I would just make sure you are eating clean and healthy foods, and dont' worry about losing weight until you are done breastfeeding. That is way too much stress on your body to cut calories when your body needs MORE calories than ever! I was always way more hungrier when bf'ing then I ever was when preggers, and I ate way more, too!