YOU SAID:

I've never not been tired ever before

INTO JAPANESE

私は今までに一度も疲れたことがない

BACK INTO ENGLISH

I have never been tired

INTO JAPANESE

疲れたことがありません

BACK INTO ENGLISH

Never tired

INTO JAPANESE

疲れない

BACK INTO ENGLISH

never tired

INTO JAPANESE

疲れない

BACK INTO ENGLISH

never tired