@Kate248
eh.. you didn't read small prints where it says "on your behalf" ... so basicly he asked you to agree that he cancels on your behalf... it is the same as you canceled. He could and should cancel without asking you to agree and without any penalty. After all it was his fault that he didn't read how much people you can host. Now you are penalized with 50-100$ , blocked dates and automated review that you canceled.
You should never cancel nor agree to cancellation.
You can contact Airbnb now , tell them that you are new unexperienced host, didn't know bla bla bla... and maybee they will unblock your dates and not penalized you if you are lucky.