I am glad you made the call to talk to someone and hope you are not too uncomfortable before you get an opportunity to tell a counselor about them.

I would stay away from the horror and murder stories and shows for a bit, maybe find some good fantasy or sci fi that has enough themes like those you appear to like but which is "out there" enough so you can practice switching your mind to the knowledge that it is not real, is not "you". Too, I would maybe do less of the reading/show watching and interact with friends and family more, do "normal" activities like chores, clean your room and get ready for school to start next month? Do you know what courses you will be taking, can you look at some of what you will be learning, get a head start of any sort?

When I am having difficulties with my thinking I jump ahead in my life like that and work on something for the future. I want to move so I am working on cleaning up this house and getting things organized to make that easier when it happens.