Do the repeated negative events a person experiences, such as aversion to studying, people's changing perception of beauty, and contracting an incurable disease, mean that God is displeased with them?

The worldly life is a realm of trial and tribulation. Patience in the face of tribulation multiplies good deeds, expiates sins, and elevates ranks. It is not necessary for tribulation to be a consequence of sin, yet sins can be a cause of calamities. Therefore, one should repent and return to Allah. The changes you experience might be due to jinn possession (mass), evil eye (ayn), or sorcery (sihr). The cure for these is through ruqyah shariyyah (Islamic exorcism) and abundant supplication.