I'm looking for a new nanny because my current (but new) nanny has updated her profile and logged in most days to the nanny website where I found her
Why do you think she's doing that?
Because she thinks I'm too demanding and she doesn't want to deal with that.
I'm sorry that you're having these nanny issues.  However, if you create a poor work environment it's expected that some people are going to just quit.  You might want to work on how you treat people that work for you.
I'm going to spank that hoe.
No wonder your nanny wants to leave. You need an attitude adjustment if you want to find a nanny to stay for a long time. Work on your behaviour, that'll be good for you in a long run.