I'm not sure about the sleeping, but are you keeping up on your vitamins? GOOD vitamins? I was taking the ones you can buy OTC at WalMart, and have been worn to an absolute rag. When I take the ones you can get (free) through prescription at the Meijer store I feel a difference in 24-48 hours, no matter how much sleep I get. I think the vitamins are literally being nursed out of me - like I don't have enough in store for both of us otherwise.
I agree about naps, or even resting. I can't get a full nap during the day, but I can have my older LO watch cartoons, and shut my eyes while I'm nursing the baby and she's napping. It doesn't always do the trick, but my body at least gets the rest. Anywho, I am 100% pro-vitamins. Keep up on your meals, water, rest, and especially the vites. God knows they're being leached right out of us! lol