YOU SAID:

I have never cooked a single day in my life

INTO JAPANESE

私は私の人生で一日も料理したことがない

BACK INTO ENGLISH

I've never cooked in my life in a day.

INTO JAPANESE

私は一日で私の人生で料理をしたことがありません。

BACK INTO ENGLISH

I've never cooked in my life in a day.