How can a fiancé get rid of the sins he committed due to the prolonged engagement period, and is there a specific supplication for the forgiveness of these sins, especially given that the family refuses to complete the marriage?

Marriage should be expedited whenever possible, in fulfillment of the Prophet's (peace be upon him) recommendation and to avoid tribulation and corruption. Guardians are advised to expedite marriage and overlook non-essential customary matters that can be dispensed with. Forgoing worldly matters is easier than compromising chastity and disobeying God's command, especially with trust in His promise: "If they are poor, Allah will enrich them from His bounty."

However, if expediting marriage is not possible, one must be patient and chaste until Allah enriches them from His bounty. Engagement is merely a promise of marriage, not a binding contract, and either party has the right to withdraw from it. The fiancé is a stranger to the fiancée before the marriage contract.

Regarding repentance from sins that occurred between the engaged couple, its conditions are: ceasing the sin, regretting it, and resolving not to return to it. Allah accepts repentance.

Finally, every person must first fear Allah's punishment for themselves, as Allah Almighty says: "O you who have believed, protect yourselves and your families from a Fire."