YOU SAID:

I should be doing my homework right now

INTO JAPANESE

今宿題をやってする必要があります。

BACK INTO ENGLISH

You must be doing his homework now.

INTO JAPANESE

あなたは今宿題をする必要があります。

BACK INTO ENGLISH

You now must do homework.

INTO JAPANESE

今、宿題を行う必要があります。

BACK INTO ENGLISH

You must do your homework now.

INTO JAPANESE

今あなたの宿題を行う必要があります。

BACK INTO ENGLISH

You must do your homework now.