YOU SAID:

I need to fall asleep

INTO JAPANESE

私は眠りにつく必要があります

BACK INTO ENGLISH

i need to go to sleep

INTO JAPANESE

私は寝る必要があります

BACK INTO ENGLISH

i need to sleep

INTO JAPANESE

私には睡眠が必要だ

BACK INTO ENGLISH

i need sleep

INTO JAPANESE

睡眠が必要だ

BACK INTO ENGLISH

i need sleep