What is your biggest fear?

Jane
Mine is claustrophobia. I have severe fear of it, just the thought of being trapped inside a giant pillow case, or stuck in a mine like the guys in Chile. It literally makes my muscles ache and I start to sweat thinking of it. 
Not sure why that's the case, maybe from childhood when my Dad would cover my head with a blanket and I would scream I couldn't breathe... Anyways 😓 what's your fear?