How can one overcome addiction to pornography and masturbation, despite repeated attempts and supplications, and feelings of despair and weak willpower, especially with the approaching wedding date?

The matter is easy with sincere repentance and truthful recourse to and reliance on Allah, and striving against the self to obey and abandon disobedience. Do not tire of repenting, and do not despair of Allah’s mercy. Keep knocking on the door of His mercy. Persist in patience, rectify slips with prompt repentance, sit with the righteous, constantly remember Allah, and reflect on death. Be keen on beneficial knowledge and acting upon it, and be truthful in supplicating to Allah, for He is the One who turns hearts.