E.C.
It is quite normal for some babies not to sleep through the night up to 3 years or more! I suggest pumping and dividing the night duties btw you and dad (esp. if he is not working right now.) But even if he returns to work soon (and hopefully) you need to make sure you are getting sleep in a minimum of 4 hour stretches in order to maintain a minimal amount of mental clarity. If you take turns with night feedings, you both get longer stretches of sleep at a time. Also, try to go to bed earlier if possible (easier said than done, I know). Any opportunity to increase your sleep will make you more effective and efficient at work and at home as a mom.
As for chaos, I've found that focusing on what needs to be done and a certain amount of ignoring unimportant pleas and whines (except for real emergencies or urgent needs) can help get the kids on board with mommy's schedule, and not vice versa. State what needs to be done once, maybe twice, and then remain silent through the rest! It's a bit like flying through a tornado, but if you can 'stay the course', you'll all be much better off in the end. ;-)
I also agree with the earlier post about getting everything ready the night before.