Oh dear. She really should not have made that tire-slashing joke to begin with, nor should she have implied that you were the client most likely to do such a thing!

She might have been freaked out by your note, but she started the joke and you were just continuing a joke that she started.

...Like, you wrote that note to draw closer to her to keep the joke going, and then the opposite happened: She pulled away.

So basically, she was afraid of you for a time and to let you know that writing such a note was not OK, she banned you for three sessions, which triggered strong abandonment fears in you. Is that what seems to have happened?

Has she calmed down now?

Was her punishment to cancel your next three sessions? How would that have solved anything?

Sometimes, when there is a rupture, it might be worth it in session to go back to the point of rupture and heal it from where it started. Have you two talked about the note and her canceling of sessions?