I think I found it. Let me know if this sounds like it. Its one I have been looking for.
The Days I Left Behind
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Author: Mewl Neko PM
SessxKag It was pure chance. They could have never met, but somehow it seemed they were destined to always run into each other. In a world where tragedy reigns, when would the sun finally burn away the shadows and the sadness.
Rated: Fiction M - English - Romance/Drama - Sesshomaru & Kagome - Chapters: 81 - Words: 247,326 - Reviews: 761 - Favs: 298 - Follows: 109 - Updated: 06-11-06 - Published: 12-29-04 - Status: Complete - id: 2194903
Spark link
www.dokuga.com/spark/story/1331/1
FF.Net
www.fanfiction.net/s/2194903/1/The-Days-I-Left-Behind
Please note this is MA.