Sooo... Everything is a lie?

What if your whole world was a lie? What if everything you had believed in was a made up story for you to believe in? When your whole world crashes down upon you, what will you do? Hermione gets to know on her 18th birthday that she isn't a muggleborn, she isn't even a Granger.
Hermione wakes up on her birthday and walks down to be met by her parents that she just a couple of weeks ago got back from Australia. But they doesn't look at all happy today.
"What's wrong?" Hermione asks her parents.
"Honey, we.. we have something to tell you. You should probably sit down." Her mother tells her.