What is the ruling regarding the past prayers of a person who made a mistake in how to wipe over socks due to ignorance, and was unable to repeat them because of obsessive doubts, and what should he do now?

Scholars have differed concerning the sufficient amount of wiping over the socks. The Hanafī madhhab holds that the obligatory amount is three fingers. The Shāfiʿī madhhab holds that the obligatory amount is the least amount that can be called "wiping." Meanwhile, the Hanbalīs are of the opinion that the sufficient amount is wiping most of the top outer part of the sock. Your prayers that you performed by wiping a small part of the top of the sock are valid according to the madhhab of Imam al-Shāfiʿī, and according to the madhhab of Abū Ḥanīfah if what you wiped was three fingers or more, and you are not required to repeat them. Beware of obsessive whispers (waswās) in purification and acts of worship after seeking Allah's help.