What is the ruling on one who has excessive doubts about the validity of her ablution and stops completing her prayer, and what should she do if she becomes unable to recite Surat Al-Fatihah in the first two rak'ahs of the obligatory prayers?

This woman has been afflicted with obsessive whispers (waswasah) due to her weak personality and lack of self-confidence. She needs to seek treatment, whether psychological, by consulting a specialized doctor, or by seeking refuge in Allah from Satan, who might whisper doubts regarding purity (tahara) or prayer (salat).

It is recommended to recite the Qur'an frequently, such as the two surahs of seeking refuge (Al-Mu'awwidhatayn), Ayatul-Kursi, Al-Fatihah, and Surahs Al-Baqarah and Aal 'Imran, to drive away Satan. She should also maintain the morning, evening, and pre-sleep remembrances (adhkar).

If the woman adheres to these matters, along with frequent supplication and earnest entreaty, her hope will not be disappointed. She must also rid herself of sins and frequently seek forgiveness.

There is no harm in seeking help from righteous sisters and attending congregational prayers at the mosque. The illness might also require ruqyah shari'ah (Islamic exorcism) from righteous people only, while being cautious of sorcerers and charlatans.