YOU SAID:
I’m very tired and should be doing my homework
INTO JAPANESE
私は非常に疲れていると私の宿題をしているはずです
BACK INTO ENGLISH
I am very tired and should have done my homework
INTO JAPANESE
私は非常に疲れているし、私の宿題をすべきだった
BACK INTO ENGLISH
I am very tired and should have done my homework
You should move to Japan!