the Fear of Fear

What is fear when it is transcends all understanding? When you aren't physically scared of something but more or less just aware of a situation.
What is it when we aren't tangibly upset or even worried but we just have an understanding that things are not the way that they should be? I would consider this FEAR but is it?
Does fear have to have feeling or can it just be an understanding? Can fear just be an awareness that something is out of place?
Can we fear fear? Can we be afraid of the feeling of fear when we put ourselves out there? Is this what causes us not to take risk? Is the fear of fear what causes us to be timid?
This goes past rejection and discomfort and this may not make sense to anyone but me but it works in my head... so I guess welcome to confusion that is my brain.