YOU SAID:
i have fallen hard for him
INTO JAPANESE
私は彼にすっかり恋に落ちてしまいました
BACK INTO ENGLISH
I fell madly in love with him
INTO JAPANESE
私は彼に夢中になって恋に落ちました
BACK INTO ENGLISH
i fell in love with him
INTO JAPANESE
私は彼に恋をした
BACK INTO ENGLISH
i fell in love with him
You've done this before, haven't you.