Not falling behind

It's only Wednesday, but already I have done more reading and "study" than I did for my whole HSC - many, many, many years ago. I am really scared that I will relax for a moment or 400 and find myself so unbelievably behind that I can't catch up. My husband says this is a good thing that will keep me on task, but waking up at 2.30 in the morning worrying that I haven't done enough yet is not going to do me much good. I guess it's about finding the happy medium - somthing I hope to do soon.