Shudder and shake

I don't get it....

I have this very uncanny feeling, and I can't shake it off.

Probably nothing is going to happen. Probably its just going to be fine, but I don't know.

My heart is racing. My senses are heightened.

My mind is going to blow soon.

I don't want to imagine. Don't want to think about it.

The waiting is the worst part.