If there’s such a thing as a “belly-up” emotion, apathy fits the bill.
Apathy is actually defined as the absence of emotion.
It’s white noise. Dead air. You feel like a chunk of flavorless tofu. Not happy. Not sad. Not angry. And certainly not passionate.
You’ve probably heard people say they knew they were out of love when they no longer got angry. The relationship had flat-lined, love had disappeared, and it wasn’t worth the effort of anger anymore.