I have yet in my life to see one person who cares about me, and it kills me to admit such a heartbreaking epiphany. Now it's grammatically correct. Contextually, ya you're using it correctly; it's being used synonymously with realization.
^ this would mean that he is using epiphany correctly because he is stating he had a sudden realization that no one cares for him or something. Which is a pretty depressing thing to say