YOU SAID:

I cannot wait to sleep for twelve hours straight

INTO JAPANESE

まっすぐ12時間寝るのが待ちきれません

BACK INTO ENGLISH

I can't wait to sleep straight for 12 hours

INTO JAPANESE

12時間まっすぐ寝るのが待ちきれません

BACK INTO ENGLISH

I can't wait to sleep straight for 12 hours