Is what happened at the beginning, the retraction of the idea about the Prophet, may Allah bless him and grant him peace, considered a mistake or an act of disbelief?

The questioner is suffering from obsessive thoughts, and she must discard these ideas and not dwell on them, for obsessive thoughts are a severe illness. The first thought did not lead to disbelief as long as it was merely a thought that she did not utter and that she disliked. A servant's dislike and aversion to satanic whispers are a sign of sound belief and strong faith, as stated in the Hadith: "That is pure faith." As for her concern with recalling the thought, it is a mistake but not considered disbelief, because it is merely a concern that she rejected.