YOU SAID:

If by then I don’t succeed

INTO JAPANESE

その時までに成功しなかったら

BACK INTO ENGLISH

If you don't succeed by then

INTO JAPANESE

それまでに成功しなければ

BACK INTO ENGLISH

If we don't succeed by then

INTO JAPANESE

それまでに成功しなければ

BACK INTO ENGLISH

If we don't succeed by then