I read a wonderful fic where Castiel was on the run from some angels who had tried to trap him in holy fire and ended up with a burn on his arm, and then he ended up hiding deep in the ocean to avoid pursuit.  He eventually made it to the Winchesters who took care of him.  I remember he was on the phone sometimes in this story, texting Sam and such, but I can't remember the title or author, unfortunately. 
Found: By Daylight and in Dream by takadainmate.

The other one I've had trouble finding is again from Castiel's perspective, and he is trapped under debris after a fight (?) and he phones the brothers because he's hurt and can't free himself from the rubble.  It's a bit of a character study since it was from Cas's point of view, and I would love to read it again.
Found: Walls Fall Down by Daylight

Thanks for any and all help!