head over heels
US /ˌhed oʊvər ˈhiːlz/
UK /ˌhed oʊvər ˈhiːlz/

1.
deeply in love
:
•
He fell head over heels in love with her the moment they met.
•
They are still head over heels for each other after twenty years of marriage.
2.
completely and utterly
:
•
He was head over heels in debt after his business failed.
•
The children were head over heels with excitement about the trip to the amusement park.