How can I repent from repeatedly looking at unlawful things, despite my commitment to prayer and acts of worship, and my awareness that "good deeds efface evil deeds"?

One must repent immediately from looking at what is forbidden before death, for good deeds do not justify returning to sins nor do they guarantee acceptance. Sins can bring sudden punishment and a bad end, and persistent indulgence in minor sins can lead to major sins and shirk (polytheism). Therefore, repent to Allah with remorse and a firm resolve not to return to sin, and do not succumb to Satan. Be keen on chastity, and marry if you are able; otherwise, you must fast. If you fall into sin, repent with a sincere repentance (remorse, abandonment of the sin, and a firm resolve not to return to it). Allah accepts the repentance of His servants, and if the sin is repeated, repeat the repentance.