According to Wikipedia, Anxiety is an emotion characterised by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different from fear in that fear is defined as the emotional response to a present threat, whereas anxiety is the anticipation of a future one.
On a personal note, I had an insane case of anxiety attack from work. It was so bad that I had to leave. It was a terrible sacrifice, but it had to be done for the sake of my mental health. I'm ok now.
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