How can a young man get rid of the lust that assails him when performing acts of worship and drives him to watch pornography and masturbate, even though he does not lust after his female colleague at work and fears falling into adultery, and he is not married and currently unable to marry, and he loves teaching the Qur’an?

The danger of the temptation of women is immense, and therefore the Sharia warned against it and set boundaries and etiquettes. It did not provide a way to fulfill desire except through marriage or what your right hand possesses. Masturbation by hand and similar acts are transgressions of God's boundaries. What is obligatory is repentance, cutting off the causes of temptation, staying away from everything that arouses desire, blocking the devil's entry points, strengthening one's connection with God and relying on Him, engaging in sports, occupying one's time with what is beneficial, befriending the righteous, and increasing supplication.