It depends on how you define "falling". The painting in which Gallifrey was trapped at the end of the war was called "Gallifrey Falls No More", which suggests that in the figurative sense of falling as succumbing to the attack from the Daleks, the planet didn't fall as a whole as it was removed from the universe itself before Daleks had complete control of it. ("The Day of the Doctor") However, individual parts of Gallifrey were said to have fallen to the Daleks before the war's ending, such as the city of Arcadia. ("Doomsday", "The Day of the Doctor").
In a more literal sense, as Gallifrey can be assumed to have been orbiting its twin suns during the war, Gallifrey was constantly falling, as an object in orbit can be described as constantly falling towards the object it is orbiting, but missing.