Are the prayers and fasting of the questioner in his early years of puberty invalid if he had doubts about the validity of his previous ghusl due to ignorance, and should one pay attention to whispers and doubts related to past acts of worship, and is it necessary to repeat the days he fasted as make-up while he was having obsessive doubts about the intention of fasting?

Doubt concerning an act of worship after its completion has no effect. Similarly, for the person afflicted with excessive doubts (waswas) regarding acts of worship, these doubts have no legal impact. Therefore, it is neither obligatory nor permissible to repeat the purification, prayer, fasting, or any other act of worship whose validity is doubted, because these doubts stem from waswas and occur after the completion of the acts of worship.