Thank you very much for your question. It is our pleasure to answer it.

In the name of Allah, We praise Him, seek His help and ask for His forgiveness. Whoever Allah guides none can misguide, and whoever He allows to fall astray, none can guide them aright.

The only solution to what you are suffering from is to ignore these whispers completely, and not pay any attention to them.

If you want to follow our advice, then we recommended that when you want to perform ablution to say Bismillaah once, and then proceed to perform ablution and do not re-wash any of your limbs, and do not wash any limb more than three times. When you want to pray, say the Takbeerat Al-Ihraam once (Allaahu Akbar); no matter how much the devil whispers to you that you did not make the intention or that there is something wrong in your prayer, then do not pay any attention to that. Be certain about the validity of your intention and your prayer (i.e., do not doubt them), and do not interrupt your prayer and start it again no matter how great those whispers are.

When you finish your prayer, no matter how much the devil whispers to you that your prayer is not acceptable, then seek refuge in Allah from the accursed Satan, and remind yourself of the Mercy of Allah that His Mercy encompasses everything, and think to yourself that you did what Allah ordained you to do and what He legislated for you and that your act of worship is valid.

Certainly, there is no cure except this, and you should know that as long as you give in to these whispers, you will continue to suffer.

And Allah knows best.