Is what has afflicted me—a reversal in my life, a change from happiness to problems and sorrow, and a loss of desire to study—due to sorcery or the evil eye?

It cannot be definitively stated that the cause of what a person is experiencing is magic or the evil eye, and it is advisable to dismiss such thoughts. One should turn to Allah Almighty by increasing supplication (dua), remembrance (dhikr), glorification (tasbih), seeking forgiveness (istighfar), and sending blessings upon the Prophet (peace be upon him), for Allah Almighty says: "Unquestionably, by the remembrance of Allah hearts are assured" and "And said, 'Ask forgiveness of your Lord. Indeed, He is ever Forgiving. He will send [rain from] the sky upon you in [abundance] and give you increase in wealth and children and make for you gardens and make for you rivers.'" It is also mentioned in the Hadith (definition) that whoever recites the dua for worry and sorrow, Allah will remove their worry and sorrow. And sending blessings upon the Prophet (peace be upon him) is sufficient to remove worries and forgive sins. A good life is for those who believe and do righteous deeds, for uprightness brings a good life in this world and the Hereafter, and inner peace and joy of heart are true blessings. Sins are among the causes of calamities and the removal of blessings, for what afflicts a servant is due to what their hands have earned, and "Indeed, a man may be deprived of provision because of a sin he commits."