Is it normal to fear that you're hallucinating your life and all the people and things in it or feel like you're in a dream or feel detached from reality if you suffer from anxiety disorder?
Anxiety can definitely produce feelings of unreality or a feeling of being in a dream and detached from your life, others or your own body.
For people who are feeling bored, stuck, frustrated or heavy, I often actually suggest that they practice seeing life as a dream... But for people who are Anxious and feeling this kind of derealization or depersonalization, I recommend working on being grounded.
Extreme anxiety tends to cause a disconnection from the body. The breath is not deep or relaxed. Deeper emotions may seem walled off, so there is only fear or anxiety or numb feeling most often.
Getting in touch and expressing buried emotions, learning to breath better, mindfulness practices, mind/body or energy work, connecting with nature, getting your bare feet on the earth regularly, and various types of therapy can all be good ways to work on the anxiety and feel more "real."
Aside from ruling out nutritional deficiencies and medical issues, anxiety is most often a symptom of deeper unexpressed emotions.
When the anxiety is dealt with and underlying feelings can emerge, things usually start to feel more mentally balanced, clear and normal again.