Quote 1
"She's not an idiot, she knows it can't happen, she's not expecting us to – to end up married, or –."
As he said it, a vivid picture formed in Harry's mind of Ginny in a white dress, marrying a tall, faceless, and unpleasant stranger. In one spiraling moment it seemed to hit him: her future was free and unencumbered, whereas his… he could see nothing but Voldemort ahead. (7.52-53)
Here, Harry starts to realize what his decision to pursue Voldemort really means; it could be the end of everything he's ever hoped for or dreamt about.
Quote 2
"Has anyone ever tried sticking a sword in Voldemort? Maybe the Ministry should put some people on to that, instead of wasting their time stripping down Deluminators or covering up breakouts from Azkaban. So this is what you've been doing, Minister, shut up in your office, trying to break open a Snitch? People are dying – I was nearly one of them – Voldemort chased me across three counties, he killed Mad-Eye Moody, but there's been no word about any of that from the ministry, has there? And you still expect us to cooperate with you!" (7.115)
Here, Harry really seizes the opportunity to lambast the Minister of Magic, Rufus Scrimgeour, for not taking action – it's clear that Harry's decision to act on his own is far removed from the official stance of the Ministry.
Quote 3
"I hate it, I hate the fact that [Voldemort] can get inside me, that I have to watch him when he's most dangerous. But I'm going to use it."
"Dumbledore –."
"Forget Dumbledore. This is my choice, nobody else's." (12.58)
Harry's finally started to act totally based on his own judgment – he realizes that nobody else's decisions or instincts are any more correct than his own, and he's wholly responsible for how he handles his connection to Voldemort, which is, after all, just between the two of them.