I am a sterile person and have no children. My wife however does not know about it as I told the physician not to tell her for fear that she would abandon me. Have I committed a sin
for not telling her about my being sterile before marriage?
You have to repent to Allah and ask His forgiveness regarding the sin you committed by not telling her about the sterility you know you have. In fact, it is considered as cheating her. However, you may beg her pardon and soothe her so that she might accept to live with you. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.