Surah Ad-Dhuha was revealed to the Prophet (Peace Be Upon Him) to relieve him of these negative feelings and to give him hope, positivity, and the assurance that Allah is with him no matter what. From it we too can find peace, hope, and a renewed faith in Allah when we go through similar states of depression, sadness, and hopelessness.
This Surah was revealed in Makkah and has 11 verses. It is narrated from the holy Prophet (Peace Be Upon Him) that ALLAH is pleased with person who recites this Surah.
If recited together with name of a person who has gone missing, he will return home safe and sound. If something is forgotten somewhere by mistake, the recitation of this Surah keeps its safe until you get it back.