Is my leaving the marital home in anger considered a sin, and is my insistence on refusing to return to my husband because of his service to his friend's wife in my absence, knowing that this arouses my jealousy, also considered a sin?

A husband does not have the right to prevent his wife from conceiving, as it is a shared right. A wife is not permitted to leave her home without her husband's permission, except out of necessity, such as seeking justice from a judge, or seeking sustenance if the husband is destitute, or seeking a religious ruling (fatwa) if the husband is not a scholar and has not sought one for her. She is also permitted to leave for essential needs that the husband does not fulfill, or if he has beaten her severely. The wife must return to her husband's home, and he is not obligated to be present to bring her back.