[TOMT] [BOOK] middle-grade/ya book about a highschool(?) girl dealing with a ghost.

I read this back in middleschool so around 2012-2014. It was from the schools library, I remember there being a romance subplot and it possibly had something to do with possession? But it was DEFINITELY about a ghost. It affected the mc physically and emotionally. I remember there being a male romantic interest and possibly a girl rival? regardless i’m struggling to find it anywhere.