How can one absolve themselves from the sin of sharing nude photos and engaging in webcam adultery with female friends, and does the following Hadith apply to this: "Whoever introduces a bad practice will bear its sin and the sin of whoever acts upon it until the Day of Resurrection"?

All praise is due to Allah, who has guided the questioner to repent from evil deeds. He must remain steadfast in Allah’s law, increase in good deeds that expiate sins, and distance himself from anything that might lead him back to such evil deeds. The effect of the sin will not harm the questioner as long as he has repented with sincere repentance, and, Allah willing, the effect of those images will not harm him. He must be wary of Satan tempting him to contact girls under the pretext of advising or admonishing them, lest this drag him back to what he used to do.