Can discarding a note containing ahadith and Quranic verses in the trash be a reason for one's affairs to worsen and become constrained, and is there a way to atone for this mistake?

You must hasten to sincere repentance to Allah Almighty, for scholars have stated that whoever sees a paper containing a Quranic verse, a Prophetic hadith, or one of the names of Allah Almighty, thrown in a dirty place, and does not pick it up, then leaving it there is considered disbelief that expels one from the faith. The expiation for this is sincere repentance and increasing good deeds, for Allah accepts the repentance of His servants and transforms their bad deeds into good ones.