How is extreme fear explained when there is no specific phobia or experience of panic attacks ?

Atypical anxiety: Extreme fear can occur in extreme generalizing anxiety disorder, post traumatic stress disorder, obsessive-compulsive disorder, and social anxiety disorder. Can also occur in organically caused anxiety disorder, anxiety caused by alcohol or drugs including medications, or in anxiety disorder not otherwise specified. Extreme fear is also felt it in pre-psychotic or psychotic disorders, especially paranoid disorder.

Many sources: Anxiety can come from chemical imbalances, a side effect of medications, external stressors, too much change in too short a period of time, and other areas. I would say go to a reputable psychotherapist immediately and talk about what anxiety means to YOU.

FEAR: Your fear may be related to the covid-19 pandemic and the stress of the unknown in how best to stay safe or a deeper fear. Consult with a Clinical Psychologist with expertise in multiple types of psychotherapy to help you with ZOOM & a Psychiatrist for medication. Follow safety precautions & hold on to hopefulness to elevate your immune system.