If the reality is as you mentioned, your Hajj is not nullified due to the sins you committed after it; you do not have to perform another Hajj to make up for this. However, it is obligatory on you to repent to Allah and to seek His Forgiveness often, perform acts of obedience, express deep regret for the sins you committed, and firmly resolve not to repeat them ever again, hoping that Allah will accept your Tawbah and forgive you your sin. Allah (Exalted be He) says (what means): (Part No. 11; Page No. 112)
And verily, I am indeed forgiving to him who repents, believes (in My Oneness, and associates none in worship with Me) and does righteous good deeds, and then remains constant in doing them, (till his death).
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.