This is one of the hardest things to give up when you have children. Little or no sleep does VERY BAD things to you. That was the biggest slap in my face when I had Dillon. The good thing about having baby #2 is you know it gets better. Brodie was better about sleeping through the night, but he will only sleep about 8-9 hours before he needs to eat again. Dillon (once he was 4 to 5 months old) sleep from 8 pm to 8 am. Funny how they are both so different.
My biggest advice is sleep when the baby sleeps and try to always remember, it DOES get better. Jason told me that ever time I got up to feed Brodie this time around. Get a cheerleader! If you don't have one, let me know - I will do it!