YOU SAID:
i am so tired and should go to bed
INTO JAPANESE
私はとても疲れているので寝るべきです
BACK INTO ENGLISH
I'm so tired that I should sleep
INTO JAPANESE
疲れたので寝なければならない
BACK INTO ENGLISH
I'm tired so I have to sleep
INTO JAPANESE
疲れたので寝なきゃ
BACK INTO ENGLISH
I'm tired so I have to sleep
You've done this before, haven't you.