How can one get rid of the feeling of guilt and divine displeasure after repenting from accumulated sins and relapsing into some of them, and the fear of a bad end, and returning to the sweetness of faith and obedience?

Masturbation is a sin and causes distress. The way to be free from it is by being mindful of Allah, avoiding temptations, remembering the seriousness of the sin, and striving for chastity and patience. The Prophet (peace be upon him) said: "Whoever seeks chastity, Allah will make him chaste, and whoever seeks patience, Allah will make him patient." One of the most important aids in overcoming it is marriage for those who can afford it. If one cannot, then they should fast, as narrated in the hadith by Ibn Mas'ud (may Allah be pleased with him): "O young people, whoever among you can afford to marry, let him do so, for it helps lower the gaze and guard one's chastity. And whoever cannot, then let him fast, for it is a shield for him." And whoever repents then returns to sin, let him not despair of repentance, but rather hasten to it again. It is reported in the Hadith Qudsi from the Prophet (peace be upon him) as he relates from his Lord: "A servant committed a sin and said: 'O Allah, forgive me my sin.' Then Allah, the Blessed and Exalted, said: 'My servant committed a sin, and he knew that he has a Lord who forgives sins and holds accountable for sins.' Then he returned and sinned again and said: 'O Lord, forgive me my sin.' Then Allah, the Blessed and Exalted, said: 'My servant committed a sin, and he knew that he has a Lord who forgives sins and holds accountable for sins.' Then he returned and sinned again and said: 'O Lord, forgive me my sin.' Then Allah, the Blessed and Exalted, said: 'My servant committed a sin, and he knew that he has a Lord who forgives sins and holds accountable for sins. Do what you wish, for I have forgiven you.'" The differences among scholars in jurisprudential matters do not justify despairing of repentance or abandoning the religion. Their differences are a mercy for the Ummah, and not based on personal whims. Returning to sins because of this disagreement is inappropriate, for the religion is from Allah Almighty, and whoever abandons it loses both this world and the Hereafter.