YOU SAID:

i’m going to sleep now

INTO JAPANESE

もう寝ます

BACK INTO ENGLISH

I am already sleeping

INTO JAPANESE

もう寝ています

BACK INTO ENGLISH

I'm already asleep

INTO JAPANESE

もう眠ってしまった

BACK INTO ENGLISH

I've already fallen asleep

INTO JAPANESE

もう眠ってしまった

BACK INTO ENGLISH

I've already fallen asleep