How can one get rid of a recurring sin that causes distress and fear of dying upon it?

The door of repentance is open until the Hour (Day of Judgment) is established. Therefore, one must repent, turn to Allah, and have a good opinion of Him, for Allah Almighty is as His servant expects Him to be. If He knows the sincerity of repentance, He will grant success and aid. Among the things that help in repentance are contemplating death and what comes after it, the destiny of the servant, and his standing before his Lord, reflecting on Allah's names and attributes, and that He is All-Seeing and All-Observing, accompanying righteous people, and increasing supplication and remembrance of Allah. Even with the repetition of sin, one must not despair and abandon repentance, but rather strive against the self until Allah grants the ability to abandon it.