I'm sure you would be frightened? scared? afraid?
What do you think you look like when you're scared? Your eyes probably open wider? Your jaw drops? Sometimes you feel like your heart stops or beats faster?
We can use idioms to show more clearly all these feelings and even the way we look. Sometimes when we're scared, instead of using adjectives like "anxious" or "frightened," we could use idioms to give the listener an image of what we've experienced.
Scare to death-
Meaning: extremely frightened
Usage: I was scared to death! / You scared her to death! / I will scare you to death with my costume / Stop scaring me to death!
Shake like a leaf-
Meaning: shaking a lot from being really scared or nervous, being extremely scared
Usage: I'm shaking like a leaf! / I always shake like a leaf when I give presentations!
Meaning: upset, anxious, excited
Usage: Don't freak out ! / You freaked me out! / Your dog freaks him out! / Let's freak someone out! They are freaking me out!
I use these idioms quite a lot, especially "freak out" because my husband loves to find ways to scare me or "freak me out". Life is always entertaining with him...