How can the husband treat the narrowness of heart he feels towards his wife, even though she is righteous and respectable, especially under difficult circumstances, and how can he repent to God?

Such incidental matters in a marital life are found in every home. As long as affection and respect are dominant in your relationship with your wife, do not worry about these incidents. Seek refuge in Allah from Satan, and increase your remembrance of Allah and your supplication to Him. Repentance is a lifelong duty that a person cannot do without at any stage of their life; it is the first, middle, and last station. Among the things that help a servant in repentance and steadfastness upon it are: seeking help from Allah Almighty, relying upon Him, striving to associate with the righteous, and frequent remembrance and supplication.