There are other explanations for hallucinations. Are these persistent images, or are they simply out of the corner of your eye? If they are not persistent, you may just be exposed to infrasound, which is a phenomenon marked by feelings of dread and nausea, as well as visual hallucinations. It's believed by scientists that infrasound is responsible for most ghost sightings.

If they are persistent, have you started taking any new medication, or changed your schedule? Hallucinations of the visual variety (auditory is a whole other beast) can be caused by stress and lack of sleep.

Unless you have a history of it in your family, chances of it are low. There are many things besides schizophrenia that can cause feelings of dread and seeing things. It is a good idea to take these problems up with a doctor, both a physical and mental doctor.

I have schizo-affective disorder sort of a mild pre-schizophrenia so I understand how scary your situation is. Let me know if you want to talk.

tbh I have NO idea what my family history is because I'm adopted from Korea and have no way of tracing my birth parents, so I don't have anything to base my genetic potentials on. But no matter what it is that I have, I REALLY don't want it ;-;

Try talking to some doctors then.