I have been meditating for several years but I cannot make sense of an experience I have had since I was in 5th grade. I will be totally relaxed while concentrating on my breathing and suddenly I have this intense rush of fear. If I had to describe it visually it is a crazy black and white scene where an infinte number of images flash before me. I feel very large like my self is peeling away from my body. Suddenly, in what feels like a split second, a million questions rush through my mind. I don't hear myself ask these questions...it's more of an overwhelmed feeling. Who am I, where am I, what am I, am I dead?? Please note I am trying to describe a feeling in terms that relate to my senses, but it is so hard to put in words. I always hear a loud screaming/wooshing noise while I feel like my head has grown to the size of a football field and I'll say to myself breathe, breathe, you are alive, you are human, etc. etc. I'll open my eyes and everything around me looks so strange...very clear, almost like a movie. I always look at my hands and body and I don't feel like they are mine. It takes me about a half hour to feel grounded again. Weird huh. This has happened to me forever. Any insight??

have you ever experienced 'night terrors'?

A man walks into a Doctors office, he raises his hand above his head and says, "Hey Doc it hurts when I do this." The Doctor replies, "Don't do that."

If you are not ready to experience dissasociation of the mind and Body it can be terrifying. Some love to go where you have gone that are addicted to psychedelic induced experiences.
You need to have a grounding point of reference when you meditate.
The purpose of meditation is to anchor the awareness in something greater than the usual day to day foundation of beliefs and experiences. The Ego self beliefs, and its foundations built of sensory experiences. The stresses of the mind and body, fear and judgment of limited programs of the minds belief system.
Knowing how to approach the infinite Self and its environment gradually and easily does not throw the body and the mind out of whack but gradually integrates it into the experience of the senses and the subtle senses. It marries the two together, the infinite and the finite.
When the mind dips into the infinite and it has no familiar anchor, it grasps to find something that it knows.
What you're describing is the mind grasping for familiarity within the realms of its mind created beliefs and boundaries as it expands beyond them. This is normal for anyone who slips beyond the relative and into the exalted boundaryless consciousness. Whether drug induced or naturally approached the situation can feel shocking to the unfamiliar mind and nervous system.
If I was you I would find a different approach, one that was created in a supported environment and one that was proven and easily accessable to all states of awareness. One that works equally and consistently for all that use the same approach.