Harry Potter was not the type of person who liked to express his feelings; he felt that outward displays of emotion were a sign of weakness. He just kept it all inside until it practically exploded and that was exactly what he was doing now. Harry refused to just break down and cry about how bad his life was just yet, he still had some pride and dignity left deep inside.
He was wallowing in self pity, more like drowning in it sometimes, and his wallowing would only be interrupted by two things; Aunt Petunia's bony hand pushing food through the cat flap that had been installed the summer after his first year. Or the call of nature. The scrap of food that was usually pushed through remained almost completely untouched, his guilt and pity ridden stomach somehow suddenly unable to keep its contents inside, a now nasty side effect of eating. His gaunt and sickly appearance did not bother him, in fact he welcomed it, it connected him with his now distant childhood, a childhood that had been brutally snatched from him at age 11. Even though it was not the happiest of childhoods it had been a time in his life that was relatively worry free and filled with wide-eyed-innocence. An innocence he no longer possessed, he had been force to grow up too quickly and yet was still treated as a child. Frustration gave way to anger, and anger turned into self loathing and pity. Sometimes his anger was directed at certain people, sometimes it was directed at wizarding kind in general, he hated having to be their saviour, a fate he could not escape. And sometimes his anger was focused at himself, for having so far let the wizarding world down, and at times, not having the strength to win this fight. Self hatred would course through his veins at this point. This is when Harry would give in and listen to the demons inside his head. They would talk of his failure, and of his inability to defeat the Dark Lord, they would laugh at him and poison his self confidence. They would tell him he was worthless and he would believe them. So it was the great Harry Potter became lost, an empty shell, a ghost of his former self, he ceased to live, he only existed.