He felt lost. In fact…lost wasn't the word used best to explain how he felt.
More abandoned and alone than anything.

Sirius was family. The last member of his real family left. He never really counted the Dursley's because they never treated him like a nephew. They only put a roof over his head and fed him. No love or affection was there.

It saddened him the short amount of time that he had got to spend with Sirius. He never deserved to die. Let alone be kept locked up and shut in the dusty old house with only a screaming portrait and a house elf to keep him company whilst everyone got to come and go as they pleased.

Harry missed Sirius. He missed receiving the letters by owl updating him of Sirius's where about, or the visits by the fire place updating him with what the order were doing. He missed the possibility that one day, when the dark times were over and Sirius's name was finally cleared, that they could live together. To be a proper family. Harry still thought that Sirius would of liked the country side after all that time that he spent cooped up in Azkaban or in Grimmauld Place.
Somewhere where his Godfather could settle.

Harry knew that he had the Weasley's supporting him, and the rest of the Order who were somewhat a dysfunctional family to him, but it wasn't the same as it were with Sirius.
Sirius was his Godfather. An extended member of the family who was like a brother to his father. One were never seen without the other.
He remembered Sirius telling him that he were always welcome at the Potter's. Harry wished he had more time with Sirius to learn what it was like growing up with his mother and father. The time he spent with them and what they were like at school. Really like. Not from the memories of Snape or not from anyone else who just 'knew' them as extraordinary people? He would have liked the chance to really get to know their personalities. He could still ask Remus, but there wasn't much hope there.
He wouldn't be able to tell it like Sirius would. There was just something about the way Sirius told stories that made him want to ask more, and really listen.

Now all he had were the mere memories of Sirius. Harry didn't know why, but he kept hoping that one day he was see his Godfather's face return in the half of the mirror that he received around Christmas time.
Deep down, Harry knew he never would.
He was alone.