YOU SAID:

I couldn't sleep last night because I was tossing and turning so much

INTO JAPANESE

昨夜は寝返りを打って眠れなかった

BACK INTO ENGLISH

I tossed and turned in my sleep last night and couldn't sleep.

INTO JAPANESE

昨晩は寝返りを打って眠れませんでした。

BACK INTO ENGLISH

I tossed and turned in my sleep last night and couldn't sleep.