YOU SAID:
i get deja vu if i dont
INTO JAPANESE
しないと既視感が出る
BACK INTO ENGLISH
If you don't, you will feel déjà vu
INTO JAPANESE
そうしないと、既視感を感じるでしょう
BACK INTO ENGLISH
Otherwise you will feel déjà vu
INTO JAPANESE
そうでなければ、既視感を感じるでしょう
BACK INTO ENGLISH
Otherwise you will feel déjà vu
That didn't even make that much sense in English.