I can't believe this is your first Snarry, well done! I particularly liked the concept of the Inanimagus (although very horrifying as well). Severus as a dresser makes sense--very solid and functional, lots of drawers with hidden contents.
I also liked details throughout: the description of Christmas at the Weasleys, Harry's discoveries in Severus' quarters, the kiss on the cheek, Severus sending Harry the apparition coordinates, the banishing of the second plate and cup. And this: "But one morning he woke up to find the knot of disquiet and anger and despair that had built up within him untangled a little, and he curled his body around Harry’s and swore that he would do anything, anything, to make the other happy." Just nicely done all the way around!!