Splinter.

Nicola is a young girl searching for her brother as her reality begins to break and splinter apart. At first she notices small things in her life changing and not making sense, people's personalities or histories different to what she remembers, then slowly nightmarish events begin to unfold, though the one constant is that her brother is missing. Nicola figures that he must be the key to this and so fights to find him, while dealing with her world tearing itself apart, and a mysterious fox creature that appears to be stalking her.