I'm not a mom, but there are a couple of things that I did that have helped our household run much more smoothly.
1. I began planning our meals a month in advance, and making a general shopping list for each week/two weeks. It's not as hard to do as it sounds, once you've done it once or twice you'll get the hang of it. I'm pretty flexible with it and don't adhere to it exactly, but it helps so much. I can look at my menu on a regular basis and know what has to be thawed, cooked, thrown in the crockpot, etc. and don't have to worry about what to feed the family if I'm in the middle of a major test, etc.
2. I cooked/prepped a bunch of meals and froze them, and I began making double batches of other meals (casseroles and soups). One we'd eat, and one I'd freeze. These meals are lifesavers during really stressful periods.
3. Buy a crockpot cookbook or two, if you don't have any. My crockpot is my best friend.
4. My husband and I talked, and he took over some of the household chores. No, he doesn't do them the way I would like for him to, and sometimes they don't get done at all, but I simply remind him if he forgets, and then ignore it. I have kept basic sanitation-type things, like cleaning the kitchen and bathrooms, but he is now in charge of the floors 3 days a week, loading/unloading the dishwasher, taking out the trash, and helping with laundry. Even having a few fewer responsibilities really helped decrease my stress levels.
5. Accept the fact that your household will not run as smoothly. It. Just. Won't. End of story. It doesn't mean that you're a bad mom, a bad housekeeper, or a failure as a woman/person. It simply means that you're in nursing school. NS is temporary, not permanent. It will end, and things will get back to a semblance of "normal" again.
You can do it!