Brilliant story. A few holes in it, such as "why didn't Harry mail his friends himself" and "why didn't he try to keep up his magic", but overall, not bad. I agree with the previous reviews though, that he'd want some form of friends or family - on the other hand, spin up the abuse angle, and he'll be unable to relate romantically to other people. Giraffe and Walruss doesn't make for a good example...
Would be nice to see a sequel.