Buffy dies and wakes up in alternate reality where she's married to Spike and Angel is his brother and she been in a coma for a couple of months... and side note Angel was married to faith for little bit.

Is it
Don't Bring Me Back to Life by Buffster1985
Ok, so I have changed the link to the story here.

Nope, but thanks ...its here on SR but cant sseeem to find it.

Might have been one by Enchantress but her work seems to have been taken down bother here and EF

You can find Enchantress's fics at Sinister Attraction. I am not sure if it was her work, it would be there, none of the summaries matched up.
Well even if my story wasn't the one you were looking for, it is a good read. It's like the one your asking for.