How can a married man with a strong sexual desire deal with his wife's inability to satisfy his sexual needs, while adhering to his religion and fearing falling into the forbidden?

May Allah grant you chastity and protect you from the evil of your semen. The essence of your question has been addressed in Fatwa No. 44504 and its related rulings. You can gently bring this to your wife's attention so she can help you. Please refer to Fatwa No. 118341. It is also recommended to consult the counseling section of the website.