Meditation And Visions

I am very confused at the moment and was wanting people's ideas and help as to what they think is going on. From a young age I have had feelings of not liking windows, mirrors and the dark. As I got older I have heard my friend talk to me even though she died, I saw a vision of another friend before he got shot even though he was 1000's of miles away. I have had gut feelings and goose pimples when I feel something is not right and it turns out to be true. I always feel like someone is watching me all the time. Last week I meditated and I heard an unusual name that I don't recognize. This voice told me to concentrate and I witnessed the start of a battle from the middle ages, I then came out of this and my head had the most excruciating pain I have ever felt. I waited 20 minutes and started to meditate again, there were images of a beach then a corn field, the sun, a dove in space swooping down to the earth and then darkness. I felt really calm and relaxed. Then out of nowhere a hissing sound, this startled me and I came out of it and found my head still hurting, I couldn't breathe, I couldn't move and I was crying. Whilst I had been in the meditative state I hadn't known that I was like this. I then felt a huge amount of grieve, I collapsed onto the floor and couldn't stop crying it was overwhelming. I tried to meditate a couple of days later and saw a woman on the beach with a thin long white dress, long wavy blonde hair I tried to speak to her but she wouldn't respond I couldn't see her face. I could feel her panic because she had lost something. I tried to help her look even though I didn't know what she had lost then she walked away and I came out of the meditative state. A week before this happened with the meditation I had a woman who I know in passing randomly tell me that I am very sensitive and I need to protect myself she is a spiritual lady and I now interested and concerned by what she means. If anyone could enlighten me on what they think is happening I would be grateful.