head over heels
1a. In a somersault; upside down; head first.
It was so dark Bob fell head over heels into a big hole in the ground.
Compare: UPSIDE DOWN.
1b. In great confusion or disorder; hastily.
The children all tried to come in the door at once, head over heels.
He was head over heels in debt.
She was head over heels in love.
Source: A Dictionary of American Idioms