Does reading the Quran from the Mushaf while reciting from memory to the teacher count as cheating, and what should be done about it?

What you are doing is cheating, and it is incumbent upon you to repent and not return to it. We urge you to strive for excellence in memorization and to persevere in this act of obedience. You can agree with your teacher to reduce the amount to be memorized so that you can memorize and master it. If that is not possible for you, and the matter is between cheating and withdrawing from the course, then you must withdraw.