What do you do when you find yourself overbooked? The VERY rare times that this happens...if its things that are just going to be cutting it WAY to fine then something has to go. Usually whatever if for the girls comes first (especially if its health related) iykwim.
Are you someone that pushes through and collapses at the end? I would push through and collapse....yep thats me.
Cancel out selectively and give yourself breathing room? Sorta answered in the question two above.
Or maybe curl up in the fetal position and cry? LOL sometimes!!! I have been known to do this when I was pregnant.....lol.