YOU SAID:
I am very depressed today, so I am not happy.
INTO JAPANESE
私は今日非常に落ち込んでいるので、私は幸せではない。
BACK INTO ENGLISH
I am not happy because I am very depressed today.
INTO JAPANESE
私は今日とても落ち込んでいるので私は幸せではない。
BACK INTO ENGLISH
I am not happy because I am very depressed today.
That didn't even make that much sense in English.