Jason thinks that his nose is far too big for his face and that it makes him look ugly. he is overly conscious of his appearance and shuns social gatherings. jason displays signs of

Body Dysmorphic Disorder  

Explanation:

Who has body dysmorphic disorder sees defects where they do not exist or is too bothered by certain features of their appearance. These people may find that they have such a repulsive physical trait that they avoid going out on the streets, avoiding social gatherings and even looking in the mirror. They become paranoid about their appearance and become very unhappy. An example of this can be seen in the question above, where Jason is so sure that his nose is too big for his face, which avoids social gatherings so people won't see him.

you so !