What is your advice and guidance for a person who has repented from reading sexually explicit material, but still imagines and recalls what they have read, and wishes to completely forget it and make a sincere repentance?

Reading stimulating stories is forbidden, and doing so with the intention of ejaculating may be considered in the meaning of prohibited masturbation. One must stop reading these stories and the like because they arouse desires. It is recommended to frequently supplicate, remember Allah, and fast, and to hasten to marry for those who are able. Whoever is unable to marry should occupy themselves with beneficial matters, such as reading the Qur'an and the Sirah (Prophet's biography), and striving against the self in acts of obedience.