Is watching games or cartoons or reading stories that include normal mixing (of genders) or private seclusion (of genders), or scenes of unreal sins like drinking alcohol, killing, and stealing, considered a sin for the one who watches or reads them, along with a request for explicit textual evidence from the Quran and Sunnah?

The mere mention of sins or their occurrence in stories or cartoons does not necessitate a ruling of their prohibition or defectiveness. They might be mentioned for condemnation and deterrence. The crucial factor here is the objective and purpose; if they do not advocate for vice or beautify sin, then there is no harm.

Regarding the questioner's situation: it is advised to consult doctors and utilize time for beneficial activities, the greatest of which is the Holy Quran, for it contains healing for what is in the chests. The Quran was revealed in stages in response to the companions' requests for stories, حديث (narrations), and dhikr (remembrance), and for all of these, they were commanded to (recite/refer to) the Quran.