YOU SAID:

I was never so wrong before

INTO JAPANESE

前に間違ってそうではなかった

BACK INTO ENGLISH

Wrong ago, so it wasn't

INTO JAPANESE

間違っている前に、それはなかったので

BACK INTO ENGLISH

It was before is wrong because

INTO JAPANESE

かつては間違っているので

BACK INTO ENGLISH

Because the former is wrong

INTO JAPANESE

前者は間違っているので

BACK INTO ENGLISH

Because the former is wrong