Biggest fears?

Mine are cancer, and death, not so much death but the idea of "eternity"...there's just something about the thought of something being never ending and it terrifies me even though I know I will never be able to comprehend it. Even thinking about me going to heaven for eternity is scary to me because although it's supposed to be perfect idk the thought of millions, billions, trillions of years being only the most negligent fraction of forever is just crazy to me. 

Anyways I kinda went off on a little rant...what about you guys what are you scared of?