YOU SAID:

I fell in love so fast that I did not see it coming

INTO JAPANESE

私はあまりに速く恋に落ちて、それが来るのを見ませんでした

BACK INTO ENGLISH

I fell in love too fast and didn't see it coming

INTO JAPANESE

私はあまりにも速く恋に落ちて、それが来るのを見ませんでした

BACK INTO ENGLISH

I fell in love too fast and didn't see it coming