i agree with harry it seemed that anyone he was close with died
lupin
sirius
dobby
tonks
his parents( he wasnt close but he could have been)
hedwig
fred
dumbledore
and he finds out that snape was there to save him and snape dies
but it has made him stronger in life he thinks about them but he goes on with his life.
i like to think like that its hard but i like to think that you cant hang back on the negatives you have to look forward to whats a head it would keep you moving, and if you lose some one dear you dont really lose them there there, every were. and they have gone some were were they cant be hurting or hurt any more. and that they enjoyed there time here on earth with the once they love. and i think that is what kept and help harry in the series.