Is it necessary to repeat my 'Isha and Fajr prayers during Duha time due to excessive flatulence at night?

If the emission of wind is continuous, such that it does not cease for a period sufficient for Wudu' and prayer, then the rulings of a person afflicted with perpetual impurity apply to you. Therefore, you are not required to repeat your 'Isha' and Fajr prayers, even if the emission lessens during the forenoon (Duha) time. Furthermore, a lack of devotion (khushu') does not invalidate the prayer.