O son, repentance is indeed a gift. One who has experienced it knows it. It's not from you, but it's all from Him. It's not that you repent first and then He forgives. It's the reverse. Because He has forgiven you, you are inspired to repent.
Abu Hafs said: "The servant has nothing to do with repentance. Repentance comes to him (from God), not from him."
And a man asked Rabia: "I have sinned much and been exceedingly disobedient. But if I repent, will He forgive me?" She replied: "No. But if He forgives you, then you will repent."
So Alhamdulillah He has made us among those who keep on repenting although it is dreadful that we keep sinning after repentance. Yahya bin Mu'adh is absolutely right in saying "One single lapse after repentance is more dreadful than 70 before it." Worse still if you are thinking about sinning again! Astaghfirullah.
Allahu humma aqnina bihalalika an haramika
wa bitho 'atika an maksiatika
May Allah enrich us with that which is halal and not the haram
And with obedience and not maksiat (transgression)
Reference: Principles of Sufism by Al-Qushayri