I'm having a hard time finding a story with sesshoumaru and kagome. I can't recall the title of author but I do remember some of the story:
Kagome finds Sesshoumaru in the future and he was turned to stone. She somehow releases him and finds out what happened. Rin was killed and he was turned to stone. She helps him by going back to the past. I think they had to be disguised and she creates necklaces to help and she also creates shinigamis(sp?). The goal is to prevent history repeat and save Rin. I think she finds him in a room, maybe under the floorboards or something like that. I thought the title included the word "fish" but I could be thinking about something else.

I think I read it on ffn.

Unsung silence By: Draconic Ban-Sidhe
A year after the Shikon was restored, she's stuck at home. Kagome wants nothing but to return to the past... until the past comes looking for her, in a most unexpected way. Can Sesshoumaru and Kagome help each other out.... or not? SxK
Rated: Fiction T - English - Angst/Adventure - Sesshomaru, Kagome H. - Chapters: 48 - Words: 329,825 - Reviews: 958 - Favs: 541 - Follows: 242 - Updated: Jan 16, 2008 - Published: Jun 28, 2006 - Status: Complete - id: 3014212

www.fanfiction.net/s/3014212/1/Unsung-Silence

There was another story with fish in the title but I cannot find that one. She broke the seal on him and I remember he slept alot in it. Think your looking for Unsung silence though.

I thought I replied to this, but just in case, I wanted to say Thank You! I'll definitely take a look.

The part about going to the past and trying to save Rin, finding him under the floorboards sounds like Tales from the House if the Moon, although the res no part about him turning to stone