Over the next few days Harry could not help noticing that there was one person within number twelve, Grimmauld Place, who did not seem wholly overjoyed that he would be returning to Hogwarts. Sirius had put up a very good show of happiness on first hearing the news, wringing Harry's hand and beaming just like the rest of them. Soon, however, he was moodier and surlier than before, talking less to everybody, even Harry, and spending increasing amounts of time shut up in his mother's room with Buckbeak.
"Don't you go feeling guilty!" said Hermione sternly, after Harry had confided some of his feelings to her and Ron while they scrubbed out a mouldy cupboard on the third floor a few days later. "You belong at Hogwarts and Sirius knows it. Personally, I think he's being selfish."
Harry Potter and the Order of the Pheonix
I think "Don't you go feeling guilty!" here is an imperative sentence. But I would expect an imperative sentence go something like: "Don't go feeling guilty, you!". The structure of "Don't you go feeling guilty!" is more like a rhetorical question. Is it a normal form of an imperative sentence? How should we understand it correctly in this context?