Why do i feel the presence of another person in my home? or am i just being paranoid?

Ok so this all began about three weeks ago. I haven't been able to fall asleep like I usually do. I mean I can really sleep when I want to. I love sleeping. I've always slept well but since 3 weeks ago, I lay awake all night trying to sleep, feeling restless and tired. And this is really unlike me. I live alone with my mother. She sleeps in her bedroom and I sleep in mine. When I woke up in the middle of the night 3 weeks ago, I was in the passage and I really felt like I saw a black shadow by the kitchen counter. The kitchen is white so it really stood out. I just shrugged it off as watching way to much horrors. It did freak me out though. After that incident I haven't been sleeping well. I feel like I'm being watched. Like there is someone in my room when I'm asleep. But when I wake up to check, there is nothing there. Feel like I'm going nuts. Oh and another thing is when I do manage to fall asleep ( very light sleep) I have the most awful dreams. Like about out of this world stuff. Of strange occurrences,sometimes of the people in my life concerning things that would never happen. This is really starting to bother me. Right now I'm in bed, hoping to sleep but I'm feeling really awake. I don't really wanna be in the rest of the house because I feel that presence again. So please tell me what is happening or am I loosing it?