YOU SAID:
I'm not tired but I really should go to sleep
INTO JAPANESE
私は疲れていませんが、本当に寝るべきです
BACK INTO ENGLISH
I'm not tired but really should sleep
INTO JAPANESE
私は疲れていませんが、本当に眠るべきです
BACK INTO ENGLISH
I'm not tired but really should sleep
That didn't even make that much sense in English.