Does The Soul Leave Your Body Sometimes?

Even though I cannot recall all of my childhood experiences. This is the one I will never forget. My school was a residential school, a very old school. So, the first experience was when we were practicing a dance for some competition. The house captain was a senior in 9th grade. She told us to keep up the practice while she went to her dorm room. We were busy practicing and then at this time I saw her again walking towards her dorm again but, she didn't spoke anything, so quiet and quick. I was a very quiet kid then. Never wondered how? It was so strange! The two experiences was with two teachers. My friends told me that the persons' life gets shorter if you see his/her soul separate from its body. I'm 18 now and I have stopped seeing things. I used to see an old-lady like figure with my teachers' face, a very very strange looking creature in our school library when it used to be closed. I liked going to the library very much so, I would just peek through the window. But, after this, I stopped going to the library when it was closed. I don't know what does all these mean? If anybody knows? Also, whenever I look to myself in the mirror I always feel as if someone is behind me! One more thing, I don't know why? But I feel as if I am going to die soon. I have always been scared of death. Why do I feel this way? Is it even normal to feel this way? I have never discussed these "feeling stuff" to anyone. Hope to get helpful solutions from you all! The two other experiences that I have mentioned above is both very similar. I would like to know if anyone has experienced the same thing as me?