Bismillah
Al-jawab billahi at-taufeeq (the answer with Allah's guidance)
Tawbah (repentance) must be performed.
Allaah Ta'ala says : "Say: 'O My slaves who have transgressed against themselves (by committing evil deeds and sins! Despair not of the mercy of Allaah; verily, Allaah forgives all sins. Truly, He is Oft-Forgiving, Most Merciful'. [39:53].
In another place Allah Ta'ala says, "Ask your Lord for forgiveness and then turn in repentance to Him," (11:3) and He says, "O you who believe! Turn in sincere repentance to Allah." (66:8)
Rasulullah (Sallallahu Alaihe Wasallam) said,"The one who repents from sin is like the one who never sinned." [Ibn Maja (3240)]
He also said, "Remorse is repentance." [Ibn Maja (4242) and Ahmad (3387)]
Please refer to this link for more information about Tawbah:
http://www.muftisays.com/qa.php?viewpage=viewQA&question=3466And Only Allah Ta'ala Knows Best.
