Paranoid about being harmed ?

Okay I have anxiety a while now. Sometimes I get this weird eerie feelings. Back then, I didn't even know what it was. I am 16 years old. Anyway, a few months ago, I don't know what made me even think of it. I guess I read something online like, "man killed wife while sleep walking" or something. I sleep in the same room with my brother and after reading that, sometimes I used to get scared of, what if my brother gets up in the night and kill me? Is this normal for anxiety? Thank God I don't worry about irrational things like that anymore, but I still get this weird eerie feeling in the late night. Help?