Here's one that sorta meets your criteria. They meet in dreams before she falls down the well
www.dokuga.com/fanfiction/story/10443/1
There's another story where she falls down the well, meets Sesshoumaru for about two years and then wakes up in her time with a lovely surprise. I've ready it countless times and can't remember the name of it. There's an OC, a water elemental named something like Akihito or whatever in it. This author has used that OC in another story of hers. And demons are alive in the future but hiding in plain sight.
Sorry I don't remember the name of it, but hopefully someone who reads this thread can tell you. I'll try to look thru my favorites too.