What is the way to overcome the lack of interest or sexual passion for one's wife, despite the interest and passion before marriage, and the frustration this has led to for both spouses?

A Muslim should be content with Allah's decree and face difficulties by taking lawful means. It is advisable to consult a trustworthy Muslim psychiatrist and to perform ruqyah (Islamic exorcism) oneself or seek it from a righteous person. If the situation does not change, patience, piety towards Allah, and persistent supplication are recommended. Separation may be the solution if the harm to the woman continues. One must also have a good opinion of Allah and be optimistic, as the situation may change with time.