Harriet,
It is hard. Maggie had IV's when she was 2 1/2 and it was hard. She was only on one every 8 hours. It was summer and my son had soccer camp to break up the day.
If you have any friends/family who offer help take it. A play date for the older ones, a friend to keep you older children busy. If there is a way to put the word out; like to a church or community group, sometimes friends offer help, food. People like to help.
I also like to keep myself distracted, get a chick lit book and read, even if it's for 15 minutes to give myself and mind a break(sometimes I would do this while Maggie is in the bath, and i'm sitting in there)
I always keep a running list on the kitchen table of questions for the doc, things that some up so as I think of it in my sleep deprived state, I will not forget.
I hope these IV's do the trick; keep us updated!