is there a anime/manga where the protagonist is a loser who's too dumb and weak to be anything useful in this world, who proceeds to live a life of never ending failiure and gradually isolates himself to come up with no functional thoughts anymore to the point where he gradually is losing his mind and intellect, to a point where nothing can even come out or inside his mind and any attempt of hope is countered by his realiziation that it's just over.

any recommendations? :DDDDDDDDDDDDD