Can anyone give me some advice on this?

Okay so I am absolutely TERRIFIED of ghosts, spirits, demons, etc. But it wasn't till when I started seeing them. First time I saw anything was back in June of 2008. I was at my Grandparents house for the weekend. I woke in the Middle of the night to the reflection of a figure in the fireplace. There kitchen shows threw the fireplaces gl cause the kitchen light was on. So I got curious and decided to look in the kitchen. Well it was about 2:30 AM so it was dark outside. So I looked in the kitchen and saw a shadow standing in it. I was half asleep so I was like "Did I really just see that?" But it was still there when I looked again. I was 13 at the time. Then in December of 2008 my cousin was telling me his basement was haunted by a little girl. I got this feeling I was being watched from behind and turned around and saw somebody in their "Dance room" which had alot of mirrors in it. I told him I could see it and we both ran up the stairs very fast. Then in May of 2011 I was in my room playing my Xbox (I am 16 years old) and I saw a white blur dart through the hallway. I got up and looked out their and there was a lady at the end of the hall trying to tell me something. I got really freaked out and shut the door really fast. And just about 2 weeks ago I woke up in the middle of the night (I had no access to the time) to something I'll never be able to get out of my head. I all the sudden got this nervous feeling in my stomach and I got this thought in my brain that said Dont move. But I turned and looked out into my room cause I was hearing breathing and footsteps. So I looked and what I say scared the **** out of me. It was not a human ghost, but it had a crooked nose, black eyes that looked like holes, pale white skin, long black hair, and looked very skinny. It was right there stairing me in the face!!! I jumped out my skin, threw the covers over my head, prayed for god to help me and make it leave, so I looked up and I felt it's presence but I couldn't see it. So my questions are 1. What did I see? 2. How can I make myself not fear ghosts anymore? and 3. Why do you think people deny spirits exist when many of us see them? And Ive been having alot of ghostly experiences this year, too many to list.