What is the reason for this sudden change from activity and excellence to laziness and negligence, and a decline in concentration and memorization, and could this be due to envy or the evil eye?

It is recommended to be patient and to make frequent supplications during times of distress. Among the well-known supplications are: "O Allah, I am Your servant, the son of Your servant..." and "O Allah, I hope for Your mercy..." and "There is no god but Allah, the Almighty, the Forbearing..." and "Allah, Allah is my Lord, I do not associate anything with Him," and "O Allah, I seek refuge in You from anxiety and sorrow..." and "There is no god but You; glory be to You! Indeed, I was among the wrongdoers," and "There is no god but Allah, the Most Generous, the Most Forbearing...". It is also recommended to consult doctors and educators specialized in psychological matters.