As far as the "feelings are two," I fall back on the modern psychological research on valence and activation. You'll see some of this on this forum if you search for circumplex or Dr. Lisa Feldman Barrett, https://lisafeldmanbarrett.com/
There's also some research here:
Russell’s (1980) Circumplex Models – Psychology of Human Emotion: An Open Access Textbook
My basic understanding, both Epicurean and modern, is that if you are alive, you are feeling something. There is no neutral state. It may be intense (high activation) or mild (low activation); and there will be an unpleasantness/pleasantness dimension (valence). But you never feel neutral if you're being honest with yourself.