How can one restore hope in success and overcome despair and failure after a period of good study?

Residing in a non-Muslim country is not permissible except out of a compelling necessity or a need that is equivalent to it, such as acquiring knowledge beneficial to Muslims that cannot be obtained elsewhere. When this necessity or need ceases, emigration becomes obligatory. As for your feelings of hopelessness, despair, and frustration, their remedy lies in strengthening your faith in Allah, for these symptoms indicate weakness of faith. A Muslim is connected to his Lord and believes in His mercy and power, so despair does not infiltrate him. Furthermore, it is necessary to organize time to perform religious and worldly duties, and to associate with righteous people who possess high aspirations.