What is the way to overcome the intense fear of straying from God again, especially when recalling past periods of straying, and how can one stop practicing masturbation and watching pornography?

I praise Allah for your diligently performing Fajr prayer and Qiyam al-Layl, and for your intention to memorize the Qur’an. Resolve to sincere repentance for past deeds, and supplicate frequently to Allah to grant you more guidance and steadfastness. Let your fear of being far from Allah be a motivator for you to remain steadfast and learn the means to do so. Masturbation and watching pornography are forbidden in Islamic law. Among the things that will help you abandon them are supplication, associating with righteous people, avoiding things that incite lust, and striving for marriage or fasting.