Duas for sincere repentance and turning back to Allah
O Allah, I seek refuge in You from the cessation of Your blessings, the change of Your protection, the suddenness of Your punishment, and all that You are displeased with. O Allah, I seek refuge in You from the evil of what I have done and the evil of what I have not done.
O Allah, I seek Your forgiveness for what I have brought forth and what I have left behind, for what I have concealed and what I have revealed, and for what You know better about me than I. You are the Advancer and You are the Delayer; there is no god but You.
Our Lord, we have wronged ourselves, and if You do not forgive us and have mercy upon us, we will surely be among the losers.