How can the sweetness of faith be restored after addiction to talking to girls and watching pornography, despite repeated attempts at repentance?

The door of repentance is open, and repentance is accepted if its conditions are met: abstaining [from the sin], regretting [it], and resolving not to return to the sin. If one returns to the sin, they should repent again.

As for speaking with polytheists, one should not begin by mentioning forbidden acts, but rather by [discussing] monotheism first, as the Prophet, peace and blessings be upon him, commanded Mu'adh ibn Jabal. However, convincing them to abandon immoralities is better than their indulgence in them.

The path of righteousness is not difficult, and its means are piety towards Allah and being conscious of Him in all circumstances, and the servant's knowledge that he will stand before his Lord and be held accountable for all his deeds.