Is prolonged wandering of the mind regarding matters of marriage and sex considered a sin and persistence in it, and a weakness in faith, especially if it increases after performing acts of worship? And is the sin doubled given that I am a female student of Islamic knowledge and reside in Mecca? What is the way to struggle against these thoughts and achieve Allah's pleasure?

Wandering thoughts and lack of devotion (khushu') in prayer are not sins, but khushu' and presence of heart are the soul of prayer and a cause for great reward. Deliberately invoking and enjoying sexual fantasies is not permissible. However, if these fantasies overcome you without being sought, there is no blame, but you should strive to repel them and not dwell on them. The root of all corruption stems from neglected thoughts (khawatir), which are the seeds sown by Satan and the self in the heart.

To safeguard thoughts, there are several methods, including: 1. Knowing that the Lord observes your heart. 2. Feeling shyness (haya') before Him. 3. Glorifying Him. 4. Fearing Him. 5. Preferring His love. 6. Fearing that these thoughts might arise and burn away faith. 7. Knowing that they are a trap to ensnare you. 8. Understanding that they cannot coexist with thoughts of faith. 9. Realizing that they are a shoreless sea that drowns the heart. 10. Recognizing that they are a valley for fools.

Sincere preparation for meeting Allah is one of the most important aids to steadfastness. Languor in acts of worship is natural, as faith increases and decreases. Its remedy is the certainty that there is no power or might except with Allah, and to supplicate to Him earnestly.

To attain the station of contentment (rida'), one must understand that Allah's decrees flow with His wisdom and mercy, and that what Allah withholds contains a good that the servant, due to his ignorance, does not perceive.

You must hold fast to Allah, supplicate to Him, seek good companionship, frequently remember death, reflect on Allah's signs, diversify acts of worship, engage in permissible recreation, and be persistent in supplication.