Extreme Headache After Dreaming

I'm 16 and for as long as I can remember I have always had dreams of things to come. I'm sorry if this all sounds like crap, but it's true.

Okay, not every dream I have is of the future, but when one is, I know for sure. When I get those dreams, I feel as though it is really happening. Now I know people say that anyway, but there is a huge difference. It feels so real that I usually mix up reality with some dreams. But the thing is, after I have one I usually can't remember them right away. I have to think about it and depict what my dream was. But the more I remember, the more I get a head splitting headache.

It usually happens in my left temple and it feels as if a hot rod is being stuck in it. But after everything and when I remember, eventually it comes true. It seems as if the more severe the headache, the less of a frame there is between my dream and it happening. Some send my heart into rapid palpitations since I have congenital heart defect, along with my nose bleeding and extreme weariness.

Some dreams I have are of the future but in my dream, they turn out worse then it actually does. For example: One day I was working at some apartments fixing some sinks. All of a sudden I remembered a dream I had some years ago. In the dream two men came outside of the apartment and started opening fire on everyone including me. I quickly started to panic not knowing what to do. I didn't know if I should run, or hide, or tell the residents. Before I knew it, two men started approaching the apartments but instead of opening fire, they met a father and it seemed as if they were good friends and nothing happened.

So my questions are; why do I get this extreme headaches? And are my dreams always worse than what really happens?