i don’t get why she made snape look like a horrible person? i also don’t understand why she waited until the last book for harry to find out that snape was in love with lily?

I don’t think she made him a bad guy just a misunderstand type of person. I mean, he had no choice to do what he did. We all are like Snape because we all are strange at times, walk on the darkside at times and other times very loyal and honorable.