I want to get rid of the devil's whispers that God will not accept my repentance?

Dispelling obsessive doubts (waswas) is achieved by contemplating the attributes of Allah Almighty that signify His mercy and grace. He is Oft-Forgiving, Most Merciful, and more merciful to His servant than a mother to her child. His mercy encompasses all things. The servant must have a good opinion of Allah, for Allah is as His servant expects Him to be. He has promised to accept the repentance of those who repent and to pardon them, if their repentance is sincere and fulfills its conditions, as in His Almighty saying: "And He it is Who accepts repentance from His servants and pardons sins" and His saying: "The acceptance of repentance by Allah is only for those who do evil in ignorance and then repent soon after. It is those whom Allah will accept in repentance." Therefore, the servant must strive to achieve sincere repentance and have a good opinion of his Lord.