As everyone else has already stated, your health is very important and you need to take care of yourself first and foremost.
Coming from the current Alumni/Spirit chair of my chapter, I can say that the new chair holder will probably be more than happy to have your help. It can be a little stressful the week before the event *at least for me* since you want to make sure that everything will be ready and everything will run smoothly. There are times that I have needed the help of my sisters and of course they stepped up.
I hope that this helps you at all...
Elena