How can a young man who has wronged himself with sins and repented to Allah rid himself of the feeling that Allah will not forgive his sins? And can he become one of Allah's saints, memorize the Quran, and be accepted by Allah after repentance? And is he considered a youth who grew up in obedience to Allah despite his previous relapse?

Allah accepts the repentance of those who repent, no matter how great their sins. Allah Almighty says: "Say, 'O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.'" Your feeling that your good deeds are not accepted is from Satan, to deprive you of acts of obedience. Therefore, get rid of it and increase your acts of obedience along with sincere repentance, so that Allah may transform your evil deeds into good ones. The guardianship (wilayah) of Allah is attained through faith and righteous deeds. The wali (guardian/friend of Allah) is the believing, pious person. Allah Almighty says: "Unquestionably, [for] the awliyaa' of Allah, there will be no fear concerning them, nor will they grieve. Those who believed and used to fear Allah."