All I've been able to find is...
Fix You, a Degrassi fanfic - FanFiction.Net
Basically summarizes the events of Live to Tell.
The Secret's in the Telling, a Degrassi fanfic - FanFiction.Net
Johnny is revealed as Darcy's rapist LOLOLOLOL
...we need better fic...
Oh, and my friend wrote this Darcy drabble which features elements of Darcy/Johnny, although it's twisted and graphic but hey, at least original and well-written:
fictionally speaking: Drabble: awakening (Degrassi, Darcy, NC-17)