YOU SAID:
I feel like I'm never going to be happy.
INTO JAPANESE
私は幸せになることは決してないだろうと感じています。
BACK INTO ENGLISH
I feel that I will never be happy.
INTO JAPANESE
私は幸せになることはないだろうと感じています。
BACK INTO ENGLISH
I feel that I will never be happy.
That didn't even make that much sense in English.