YOU SAID:

He's head over heels for me

INTO JAPANESE

彼は私のために頭を越している

BACK INTO ENGLISH

He's over his head for me.

INTO JAPANESE

彼は私のために頭の上にいる。

BACK INTO ENGLISH

He's on his head for me.

INTO JAPANESE

彼は私のために彼の頭の上にあります。

BACK INTO ENGLISH

He's on his head for me.