I so agree with Katherine, doing all the planning and stuff yourself without parents trying to tell you how to do it is much less stressful, although my mother did manage to stress me out on the day with her poor time keeping and appaling sense of timing Bless her!
My mother in law was great and tried to keep me and my stress levels under control. Not many people say they get on with their mother in law, but I have a better relationship with her than my own mother

. We didn't set off for our honeymoon until the following morning. I didn't make it until the death of the disco (once upon a time I would be the last one to leave:lol
I, at that point had not been diagnosed, but it did take it's toll on me, but then I had no idea what was going on... I didn't end up in hospital just very very tired.
Just remember to take each day running up to your big day as it comes, make sure you get plenty of rest and relaxation when you can. If you can on the day, my husband and I took ourselves off for an hour or so just to have some time together and a break from our guests!!
Wishing you all the best!!!
Claire