What is the ruling regarding the prayers I previously missed based on an erroneous fatwa, estimated at approximately 150 days?

Yellowish and brownish discharges connected to menstruation are subject to the rulings of menstruation, provided that the total duration of menstruation and the connected discharges does not exceed fifteen days. If the yellowish discharge is connected to the blood and is not interrupted by a period of purity, then the total of those days is considered menstruation, and abstaining from prayer during them is the correct course of action. However, if a woman sees yellowish discharge after seeing a sign of purity, or if its duration, when added to the menstrual period, exceeds fifteen days, then it is subject to the rulings of istihada (non-menstrual bleeding), and she must perform ablution for each prayer and make up the missed prayers according to the majority of scholars. Shaykh al-Islam, however, holds the view that making up prayers is not obligatory in this case.