Does the expiation for masturbation—in the form of making up prayers and fasting, and feeding the poor—fall away from me if I was previously unaware of the obligation of ghusl for janabah?

Fasting while in a state of major ritual impurity (janabah) before Fajr is valid. However, practicing masturbation during daylight hours of fasting invalidates the fast due to the emission of semen. Nevertheless, if one is ignorant of this ruling, their fast is not invalidated, and they are not required to make up for it. As for praying without performing ghusl (ritual bath), making up the prayer is more cautious and represents the view of the majority of scholars.