Is it necessary for the worshipper not to repeat words that he utters nervously in Al-Fatiha or Tashahhud due to obsessive whispering, considering that this came out of him involuntarily and unintentionally, so as not to exacerbate the state of disquiet and lead to missing the prayer?

Whoever doubts their prayer and recitation after ablution should not pay attention to this doubt and should treat themselves as if they were correct and their recitation was valid. This is because doubt is a whisper from Satan, and the best cure for it is to ignore it. The person afflicted with obsessive thoughts should have a good opinion of Allah and remember that trials afflict the Prophets, then those who are most like them, and then those who are next most like them, in order to raise ranks and expiate sins. One must be careful not to be negligent in prayer and should make up any missed prayers, and supplicate frequently and sincerely.