I think you should spend the rest of the day (apart from lookong after yourself!) finding another job.
These people, like Heswall, are inconsiderate employers.
People like this seem to have no idea that they are employing somebody. Treatment like this, and the manner Heswall alludes to, are redolent of slave conditions, not appropriate conditions for an employee!
Flexibility is an admirable quality, but you are being taken for granted and this is being massively exploited.
They evidently don't care about you or your own situation.
People who treat their nannies like this make my blood boil.
Oh, and ignore comments here about what you were doing being on MN! Bibbity can't work a 24 hr clock
and others who made such comments have no idea of the realities of your day.
Good luck to you, and i hope you feel better soon.