Answer:
agoraphobia.
Explanation:
Agoraphobia: In abnormal psychology, the term "agoraphobia" is described as one of the different types of anxiety disorder in which an individual feels fear and therefore avoids visiting different situations and places that can often lead to create panic and make him or her feel embarrassed, trapped, and helpless. It generally starts as a complication related to anxiety disorder, panic disorder, etc. However, it tends to occur or develop between the age of thirteen to thirty-five years.
In the question above, Walter is being diagnosed with agoraphobia.