YOU SAID:

Whatever it is that is eating you, it must be suffering horribly.

INTO JAPANESE

あれを食べるときは、それに恐ろしく苦しんでする必要があります。

BACK INTO ENGLISH

When you eat it, it must suffer horribly.

INTO JAPANESE

それを食べるときは、恐ろしく苦しむ必要があります。

BACK INTO ENGLISH

You must suffer horribly when you eat it.

INTO JAPANESE

あなたは、あなたがそれを食べるとき恐ろしく苦しまなければなりません。

BACK INTO ENGLISH

When you eat it you must suffer horribly.

INTO JAPANESE

それを食べるとき恐ろしく苦しむ必要があります。

BACK INTO ENGLISH

You must suffer horribly when you eat it.

INTO JAPANESE

あなたは、あなたがそれを食べるとき恐ろしく苦しまなければなりません。

BACK INTO ENGLISH

When you eat it you must suffer horribly.

INTO JAPANESE

それを食べるとき恐ろしく苦しむ必要があります。