There was so much I liked about this story. Describing Draco's needs the way you did and having Guardian as his release made a lot of sense. At the same time, there was the building relationship with Harry that, as it grew separately, felt very realistic and separate. That's why I was disappointed that the ending felt too cliched, with Guardian = Harry, and Draco just accepting that without even a hint at anger for being lied to for so long. I guess it fits for the "fanon" category, just ... as a story it lost some of its credibility there, which is a shame because otherwise I quite liked how you handled the BDSM component.