You are an amazing author. There is no doubt about it. As a reader, I personally found this chapter, especially the 'talk' that Snape had with Harry HIGHLY disturbing. I had to fight myself to read through it. THIS Snape in unfit to be anybody's guardian. Being abused himself, he doesn't recognize the signed of an abuse victim and definitely doesn't have the ability to deal with one.
He tried to tell Harry that he can be good at his studies by saying "doesn't your TINY BRAIN comprehend..." He went on to threatening him in order for him to refrain from misbehaving and putting himself in danger, rather than explaining to him.
Harry doesn't remember his parents, yet the first thing Snape tells Harry about James is that he was a bully. Just because he can't get over his schoolboy grudge and insecurities, he dragged Harry into it. Harry being bullied himself is obviously going to despise his father for being one. Then he went on to being overly satisfied for his nemesis's son to apologize to him on belhalf on his father. He thinks he's gotten his revenge by doing so?
After ruining a father's (who dies protecting him) image in his son's eyes he says not to "think too harshly of your father."
I believe children should NEVER be dragged into their parents' affairs or be told of their negative actions when they are so loving and caring towards their children.
I honestly hope he changes quickly and I can keep enjoying your writing.