Is the wife considered sinful for refusing marital intimacy due to her husband's sexual dysfunction and his refusal to find solutions for this problem?

A wife must obey her husband in matters of intimacy as long as he provides for her appropriately, except for a valid excuse such as illness, menstruation, an obligatory fast, or harm resulting from intercourse. Her aversion or potential hardship does not permit her to refuse. The husband should seek permissible treatment for any weakness he experiences so that he can fulfill his wife's needs.