Is it obligatory to make up the prayers that were performed too quickly for 5 or 6 years, and how does one make up approximately 10,000 prayers? And is it obligatory to re-perform the prayers and fast the days that were observed in Ramadan due to not knowing about the obligation of ghusl after menstruation?

Tranquility (طمأنينة) is a pillar of prayer, so whoever prays without it, their prayer is invalid, and they must repeat it as long as the time for it remains. As for past prayers, if the lack of tranquility in them was due to negligence and knowledge of its obligation, then repetition is required by consensus. If they were ignorant, the majority of scholars hold that repetition is obligatory, while some scholars maintain that repetition is not required. The view that repetition is required is more cautious and absolves one of responsibility.

The same ruling applies to prayers performed without ghusl after menstruation.

However, fasting during which ghusl from menstruation was not performed is valid, as ghusl is not a condition for the validity of fasting; rather, purity itself is the condition.