Those other responses highlighted something important here - for most women it takes almost a year to get back to their pre-pregnancy weight. You are completely on the right track, just be patient! The only thing I didn't see on the list was drinking plenty of water. I'm sure you do, since you have such a great workout routine, but getting plenty of fluids will both help you feel fuller and prevent your body from thinking it needs to retain extra water/nutrients. It also helps keep breastmilk going (although I didn't see that in your post).
Finally, you hit the nail on the head for sleep deprivation! Once your baby settles into a regular sleep routine, then you'll see a difference. I have a 4 month old at home, and I lost 20 pounds right away but then didn't lose anything for over a month! Since then I've lost about 2 pounds a week, but I had some extra pounds to drop since I totally blew my workout routine last year. Now I'm gardening in the mornings and walking at night, which makes my energy levels higher, too.
If you're really concerned - ask your doctor. I had a couple of girlfriends who really struggled to lose the baby pounds, and when they talked to the doctor, tests revealed they had a thyroid condition.
Best Wishes, and Congratulations!