I think he "MIGHT" be suffering from
obsessive compulsive personality disorder.
You are obsessive with yourself and really wanting the way
things they are, learn to let go.
Who know that you already quite fit at your age?
You might have friends but you dont realize
and appreciate it?
What is the definition of nice clothes?
Even if you fail all subject and academically declined, you
might be good in something else like ART and SPORTS?
I think you need to seek help from parents or
teachers.