I spent so much of it wanting to smack Severus over the head, while also realizing what a sad and pathetic life he'd had to make him the way he was. I was pleased that Harry made him work for it once Severus started to come around.
I'll admit I'd suspected something of the sort when Severus unravelled the mystery. It was still heartbreaking to see Harry suffer (and Severus too; though he was still getting a bit of his own back). You did a great job of hiding clues and combining canon and fanon.
I'm glad they got a happy ending. They both deserved it.