I'm sorry to be the bearer of bad news (as if you don't know this anyway), but you will never ever sleep as wonderfully as you did pre-pregnancy and certainly not pre-baby. It's just the sad truth of having a wonderful baby around the house.
"Sleeping through the night" is going to take on a whole new meaning. I recall when Owen first slept four straight hours. We called that the new "sleeping through the night." It was wonderful, amazing, incredible.
I just recall being totally unprepared for how much lack of sleep would affect me. I know it was Mother Nature's way of preparing me slightly for the lack of sleep when in the third trimester of pregnancy I no longer could sleep well. Still, nothing will truly prepare you for what it's like to be living on such little sleep.
Some tips for surviving it:
1. Sleep when baby sleeps. Seriously. This is the best advice I never took! It is the one thing I definitely regret about having a newborn. I took advantage of those times when Owen would sleep as times for me to take a shower, clean up the kitchen, fold laundry, write thank you notes or in the baby book, check Facebook, upload pictures, etc. All things that could have waited. I wish I had lie down for even short naps while he slept. You need that time to recover and rest.
2. Get into a system with your husband of who will wake up at certain times and make sure you plan out that on maybe Saturday you get to "sleep in" (another term that will take on new meaning after baby arrives)and then the other person sleeps later on Sunday. Take turns!
3. Say no - Do whatever it is that makes you feel OK at a certain time. If you wake up on Sunday morning and just cannot imagine getting out the door in time for church, so be it, you'll go when baby gets bigger and isn't making you up all night. If you're invited to a party that interferes with the only nap time your kid is routinely taking and therefore your only time to rest as well, decline the invitation politely and rest up. It's OK to bend the rules a bit when things are so hectic.
4. Stay nourished - Eat frequently and whatever it is that makes you feel good. Yes, it'd be great to get in some fruits and veggies, and definitely protein to stick with you longer. However, during those first two months of sleepless nights it's best to just indulge in whatever it is that will make you feel taken care of and nourished. Keep healthy snacks around for those hunger pangs that hit you randomly. Something that I read about this that made me feel less guilty eating at 3 in the morning was that being awake more hours means your body needs more calories and nutrients to keep it going, therefore you must eat more than you would if you were asleep. EAT. It's OK. Really.
5. Stay hydrated - Drink tons of water. It helps with everything - the way your skin looks despite the bags under your eyes, how refreshed you feel, your ability to fight off colds despite being run down, etc. If you are nursing you'll need to drink tons of water anyway, so it's just a good idea.
6. Ask someone to come over and watch baby while you nap. I never did this but totally should have. With your first baby you feel overwhelmingly at times that it's all on your shoulders, that you have to and want to be there for every single moment. And yet baby sleeps a lot, too. So if you can, ask someone to come over and watch baby while s/he sleeps so you can truly rest. Even a half hour will help.
7. Keep to a routine - Once you get past the first few months of baby being on the every two hour schedule that is natural for her body, try to get her on a schedule that is routine and something you both can expect. This happened for Owen around 3 months old and has stuck and worked perfectly. It wasn't anything we did really, just what his natural rhythyms asked for. However, we made sure nothing interfered with it so that it became routine and something that worked for everyone.
The last thing I want to say is that I know for sure you WILL survive the sleepless nights. I promise you it gets better eventually. I know there will be moments, especailly as you return to work, that you question if you can go on one more day with being woken up in the night so frequently. The answer is yes, of course you'll go on and be great. It's just a developmental stage your baby is going through. All parents remember it and get through it just fine. You will, too.