YOU SAID:

I guess I should go to sleep

INTO JAPANESE

私は寝るとする必要があります推測

BACK INTO ENGLISH

Need to go to bed I guess

INTO JAPANESE

寝る私は推測する必要があります。

BACK INTO ENGLISH

You must go to bed I guess.

INTO JAPANESE

ねベッドに行く必要があります。

BACK INTO ENGLISH

I must go to bed.

INTO JAPANESE

私はベッドに行かなければなりません。

BACK INTO ENGLISH

I have to go to bed.

INTO JAPANESE

私はベッドに行かなければなりません。

BACK INTO ENGLISH

I have to go to bed.