Psychic? Possession? Schizo? Help!

I'm eighteen and I've been seeing ghosts almost for as long as I can remember. About two years ago, when I was 15-16 is when my "psychic abilities" had increased, to the point where I started to have epileptic seizures (although I've never been diagnosed with epilepsy.) I would wake up to shadow figures standing over me, by the end of my bed, or the other side of it. I told my grandmother and she told she saw a ghost at this time, too. (we live in the same house.) At one point, I was trying to take a nap and I couldn't wake up, move my body, etc. I was completely paralyzed! It was like my spirit had awoken before my body. Later on, we found out that the old man behind us had died. Once my grandmother and I was informed on this, all the seizures/sleep paralysis went away. The only other person who knows about these 'abilities' is my sister. She told me she experienced something similar. I definitely feel like the old mans spirit was trying to inform us he passed away, but I don't know what for.

Well I've moved out last year and I still have the strong feeling that I'm being watched or that there's a ghost in my house. Actually, that feeling has happened quite frequently but all of sudden and out of nowhere it's getting stronger. I have to slee with the lights on just to feel like I'm not being watched. Also, this only happens when I'm in the shower and I feel like it's because running bath water sounds like white noise or I'm just losing my mind, but I started hearing voices through the water. I can't make out what they're saying but it gets to the point where I have to turn the water off for a few minutes to make sure no one is in my house. But sure enough, once I turn the water back on, there's the voices again. I know I sound crazy, but I don't think I have some type of schizophrenia or any other mental illness. For the longest time I've always felt like I was psychic but I didn't think so because I can't just turn it on and off. It happens whether I want it to or not.

So, I guess what I'm basically trying to ask is. What is the correct term for this? I don't meditate so I don't think I'm a medium. And also, do you guys have similar abilities?