Is fasting two consecutive months as an expiation sufficient for intentionally breaking the fast in Ramadan in two consecutive years, with doubt about the occurrence of intercourse and not remembering the number of days?

The door of repentance is open and will not close until the sun rises from the west. So praise Allah that He has accepted your repentance, have a good opinion of Him, and turn to Him. Allah accepts repentance from His servants and forgives evil deeds. No matter how great the sin, Allah's mercy is greater, and Allah forgives all sins for whoever repents with sincere repentance. Allah Almighty said: "Say, 'O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.'" And the one who repents from sin is like one who has no sin. Be sincere in your repentance and do many good deeds. Intentionally breaking the fast in Ramadan necessitates making up the days you missed, and you are only required to make up what you are certain you broke. Your doubt about intercourse from the anus does not necessitate expiation, because the default is that it did not occur, and expiation is due for breaking the fast with certain intercourse.