I have nothing against Snape, he is my favourite character, except there must be a chance that, his love for Lily is an obsession, and when she died, he was crazy about it and thinking. Though, what I mean, is that was that at one part of his allegiance, that once he convinced Dumbledore of his love to Lily, then he wasnt protecting Harry for Lily, but for his own gain?
Just a theory
Just a theory