How can a young man rid himself of the addiction to masturbation and pornography, and stop repeating the sin, especially with the continued desire to commit disobedience even during acts of worship, and his feeling of envy towards married people?

The ideal remedy is marriage. If you are unable to, then you must fast, supplicate, and humble yourself before Allah, asking Him to avert evil from you. It is necessary to guard your thoughts and ward off evil ideas, replacing them with beneficial ones. Accompany righteous people, frequent mosques and gatherings of remembrance (dhikr), stay away from forbidden things, and reduce time spent in solitude. As for envy, if you see someone whose envy you fear, say: "Whatever Allah wills! There is no strength except with Allah."