After having had two babies myself, I can't even imagine how important losing weight seems to be to you. Your original post doesn't mention whether you're breast feeding bub or not, but if you are, you have to know that his nutrients come from what you put in your mouth. If you limit your food intake, especially meats and carbs, you limit what he gets from you. I know how it feels to gain weight with your pregnancy, so don't feel that I'm attacking you, but just be aware that it's not just about you any more. Even if you're not breast feeding him, the energy requirements for being awake throughout the night and loosing weight at the rate you desire, will eventually catch up with you if you don't put enough in.
I guess it's just a case of "different strokes for different folks", but please just think about it.