I can't seem to find it for the life of me. I've been going through the tags here and my bookmarked tags. Its post mystery spot where Sam and Dean goes hunting the same hunts Sam did during those 6 months. Sam was being very overprotective of Dean. One of the points of the story, i think, was that Sam knows about the vampire next and decides to send Dean elsewhere to take care of the vampire next himself, rather than have Dean hurt. Let me know if this rings a bell. Thanks so much!