What is the interpretation of the confusion and obsessive thoughts that afflicted me after seeing the Prophet, may Allah bless him and grant him peace, in a dream, and is this vision real or not, especially with the feeling of joy and certainty during it?

You must distance yourself from whispers (waswasah), for they are from Satan. What you mentioned is correct: Satan does not take the form of the Prophet, peace and blessings be upon him, and whoever sees him in a dream has indeed seen him, and lying about him is severe. Therefore, there is no need for confusion. If you are certain of what you saw, then narrate it; otherwise, there is no harm in not doing so. You should also recite the Quran, engage in remembrance (dhikr), seek refuge [with Allah], and ask for forgiveness to repel Satan.