empty
be running on empty have exhausted all your resources or sustenance.
☞ The image is of a vehicle's fuel tank that has run dry. The same idea is expressed by be running on fumes.
2019Guardian All that remains are tired minds and tired bodies. None more so than Theresa May's: the prime minister is running on fumes.
empty nester a person whose children have grown up and left home. informal
empty vessels make most noise (or sound) those with least wisdom or knowledge are always the most talkative. proverb
☞ Vessel here refers to a hollow container, such as a bowl or cask, rather than a ship.