I had a friend asking me what I did to get used to a new baby in the house. Here are my suggestions to her:
Get on a schedule. That whole thing about 'sleep when the baby sleeps' only works if you have one baby. When you have a new baby plus a two-year-old running around, there's no way to nap when the baby naps, so you have to buckle down and get the whole family on a routine. On the rare occasion they may both be sleeping at the same time, lay down even if you cannot get any actual sleep.
So many new moms make the mistake of trying to get things done while the kids are sleeping. I would encourage Instead, I suggest you schedule your activity concurrent with theirs. My kids loved to color or play a game in the kitchen while I fixed dinner. It is noisy. But at least we were both getting things done and they were where I could keep an eye on them.
Accept help. If someone offers to watch either of them for a few hours, say YES. Even if you prefer to keep the visitors to a minimum and think you are doing well, you need this.
Get some sleep. The only real cure for lack of sleep is sleep. You may be deprived for a while, but get some sleep whenever you can and note that the quality of the sleep is as important as the quantity, so when you can, make it as restful a sleep as possible.
When you are sleep deprived you can suffer from numerous negative effects that lack of sleep causes including irritability, loss of emotional control. Pro-longed sleep deprivation can impair your immune system making you more susceptible to getting sick and fighting off infections. Because you are tired, you may start eating more to compensate for the lack of energy and your metabolism will get sluggish - making it harder to lose the baby fat and susceptible to gaining weight. It even impairs your memory and physical coordination.
Just remember, you can do this and breath!