the bottom falls out of (one's) world
Someone loses their entire sense of happiness, purpose, motivation, or confidence. His entire life was devoted to becoming a fighter pilot, so the bottom fell out of his world when an injury from a car accident meant he could no longer fly.
the bottom falls out of your world
If the bottom falls out of your world, something bad happens that changes your life and makes you very unhappy. When our son was arrested, the bottom fell out of our world.