It could be sleep deprivation, as it has happened to me aswell during times i havent been getting good amounts of sleep (8-10hr). if that not the cause then tell a docter, also include the details of what your seeing, people, physical/facial/etc descriptions. otherwise im sorry for you
This sounds really hard. My son has had a major mental health spiral of depression and has intense anxiety and ocd that causes intrusive thoughts. Been very rough. Because he has been suicidal, I'm sleeping near him. If you've had a physical, do begin looking into your mental health. My son is plagued by nightmares. He's working through some trauma. Because you are in a state of trying to rest, maybe in an early stage of sleeping, it gives you an altered perception that someone is watching.this must be very distressing to you. Talk to your parents and come up with a plan to work on this.
You need to see a doctor. If the doctor doesn't see anything physiological that might be causing this, you will probably be referred to a psychologist for a diagnosis of your mental health.