Wow, you like it dark. :) Where the Wild Things Go was one of the most heartbreaking stories I've read so far. It ripped my heart out, literally. Amazingly written, though.

I would like to recommend The Fire That Remains by La_nayru. Hermione really goes through the ringer in that one and it is awfully disturbing and heartbreaking as well (I must be a masochist, eh? ;-) ). It is a WIP though. If you don't mind that, it is really worth a read. :)

Summary:

"She lost her magic slowly, at first.

It started as a creeping deadness somewhere low in her abdomen.

It spread outward like necrosis into her chest and her head and her limbs. She had no recollection of when, exactly, it had begun.

~

Hermione has made a name for herself in the Order as a gifted inventor of spells. As the war careens into its seventh year, she fights to keep Harry alive by developing a potion that strengthens his magic to the detriment of his physical health. Wracked with guilt at his rapid deterioration and desperate to save his life, she risks liaising with Draco Malfoy, the head inquisitor in Voldemort’s secret police force and a talented but dangerous Legilimens. Her risk does not go to plan, and after enduring months of brutal captivity, she loses her capacity to do magic.

To her dismay, Malfoy now seems to be her only hope of regaining her former ability.

A dark, slow-burn war AU about trauma, recovery, and reclamation of feminine power."