What is the practical and detailed solution to the problem of obsessive-compulsive disorder (OCD) in acts of worship, especially concerning the intention to interrupt prayer, Wudu (ablution), and Ghusl (ritual bath), knowing that the questioner suffers from weak willpower in resisting these obsessions? What is the ruling on performing Tayammum (dry ablution) in this situation when water is available, and how is Tayammum performed? What is the advice regarding the obsession with excessive recitation of Al-Fatiha?

The optimal treatment for waswas (obsessive whispering/thoughts) is to ignore it, no matter how intense it becomes. With struggle (mujahadah), the matter will become easy. Whenever Satan whispers to interrupt the prayer or that the intention (niyyah) is not present, one must continue the prayer and pay no attention to the waswas, for it is valid. The same applies to ablution (wudu) and ritual bath (ghusl): do not hesitate, do not interrupt your ablution, or re-wash limbs, no matter how much Satan whispers that the intention has been broken, because breaking the intention during ablution does not invalidate what has already been washed. Similarly, when reciting Al-Fatiha, pronounce each letter once without repetition or exaggeration in articulating the exit points of the letters, as this is blameworthy extremism (tanattu') and diminishes khushu' (devotional humility).