Predatory Teacher Plotting With Police

I am a student at a low-performing high school. A predatory teacher, who I think passes through a few different subjects before ending up as my Spanish teacher, is targeting me before turning his attention to my friend, who I will call Hannah. She agrees to go to prom with him. My other friends and I plan to all go to prom together as a group in order to keep her safe. When we make this plan, one of the boys indicates that he had been wanting to go specifically with me and I get stomach butterflies.

We go to Hannah's house before prom to keep her from going. Unknown to me, one of these friends brought a gun to kill the teacher with. When he shows up she grabs him and he grabs Hannah. Gun-friend shoots him but the bullet goes through his head without really hurting him and into Hannah's head, killing her. As teacher starts trying to kill my friends, I run off through his house to find a phone to call the police to with without disturbing his elderly mother, who he lives with. I manage to report the murders in progress right as I am discovered and run out of the house, the cops saying someone is out in front to rescue me. But they aren't there and I realize they are in cahoots with the teacher and are planning to make me think I am insane before killing me off too