Snape and Harry

I’m currently rereading the books and I’m on the Half-Blood Prince. I have some thoughts about Snape that I’m sure have been brought up before, but I’m new to this sub so please forgive me.

This whole time I’ve been rereading, I’ve been thinking to myself that I don’t know how Snape can look Harry in the eyes, let alone treat him in such a terrible manner, given that he played a significant role in making Harry an orphan. If I was a big reason that a kid had to grow up without parents, I wouldn’t be able to be in their presence without feeling intensely overwhelming guilt, especially if I was secretly in love with one of those parents I helped kill. Snape’s nerve astounds me.

There’s a lot of criticism for Dumbledore, but I think one of his biggest failings is allowing Snape to be such a horrible human, especially to Harry since Dumbledore knew that Snape sent Voldemort after Lily and James.