Do you take any medication prescribed by a doctor? I know of someone who started on Prednisolone (a corticosteroid) and he started hearing voices and seeing someone, especially at night.
The package information leaflet for Prednisolone reads:
Mental health problems can happen when taking steroids. These illnesses can be serious. Most of these problems go away if the dose is lowered or stopped.
If you are on any pills check the information leaflet for side effects pertaining to mental health.
Do you watch horror films on a night? If so, stop. I don't know how young you are but you might grow out of it as your mind and brain develop but this is just my own idea nothing I've read or been told.
I've been looking after someone for two years who suffers from schizophrenia and I've learnt a bit from the nurses, doctors and other patients.
If you do need medications bear in mind
Clozapine and read the link below. Someone else I know been on it for 10 years and holds a job down and is normal now. A stressful event, death of father, brought it on, followed by heavy drinking.
https://en.wikipedia.org/wiki/Clozapine
I would
keep a journal of all these events with time date and a description and show it to a doctor if things get really bad.
Maintain your
immune system. No drugs, booze, cigs, plenty sleep and good food and lose weight if a fat. A psychiatrist told me the patient, when I was visiting with him, no coffee just tea or water, hot or cold.
I hope you get better. It's shocking how many people suffer from serious mental health. My friend became someone else and attacked me with blows to face, foot and bites. I've actually seen him talking to an invisible person and he used long complicated words and sentences just on the cusp of understanding. I wouldn't have believed it if I hadn't seen it for myself.
in the dark. I also talk to myself more and now talk to myself in public. I think the loneliness is taking its toll on my brain. 
