How can I help my husband stop talking to women and asking for their nude pictures, knowing that he is kind and affectionate and does not fall short with me, but he has been afflicted with this matter, and what should I do about it?

The wife should deal wisely and calmly with her husband's whims, and contain the situation by drawing closer to him and beautifying herself for him, and by making abundant supplications for his guidance. She should remind him of Allah and the consequences of sins, either secretly or indirectly, such as through impactful videos and Islamic booklets, and remind him of his children and that their righteousness stems from the righteousness of their parents, and of the dangers of violating Allah's sacred limits in secret. If he does not respond, she can frankly tell him what she has learned with gentleness and love, and remind him of Allah's expansive repentance.