Practical tips I've picked up:
Get a couple of waterproof (non noisy) bedsheets. Make up childs bed with however many layers of sets you can. So i have matress, waterproof, fitted sheet, waterproof, fitted sheet. That way if a night time wee or puke occours i can ninja strip the bed and have a ready made bed to go underneath. I also have a spare duvet with a cover on it in case top ones gets soiled.
Get a puke vessel. I chose a kitchen tupperware, large, with a lid and handle. If you're sick too you can seal the lid until you can make it to the bathroom to clean up.
Stock up on vitamins and any meds you might need..calpol, baby ibuprofen, thermometer, chicken pox cooling foam. Whatever it is, get it in and then it's there when you need it.
Nesquick. My kid won't take medicine direct from the syringe or spoon. I make a very small milkshake (not too much as if they don't finish it you wont know how much medicine they took down). I add the meds to this and just tell them its a yummy milkshake for your throat.
Wipes and Dettol areosol spray. If you're unwell too at least you can spray loo, flush, handles in between boats of d and v till you can get to it properly
Ice lollies and watermelon are good for kids who refuse to drink much if they're ill
Finally, just keep telling yourself you'll get through, because you will.