What Causes Severe Headache While Sleeping?

Hi! My name is Muhammad Ali and I am from Pakistan. I have a problem form many years that i feel a swear pain in my head during sleeping. And this is so strong that sometimes I feel that my last time is came. It starts that my brain is present that i can feel change,but connection of my brain with my body is broken and I cannot move my body part even if I try it hard. Then gradually pain started and the pain go on increasing. I can feel that something is going on in my mind but what is it . I don t know. So, whats your suggestion to me. Tell me that it is some kind of a serious disease or I don t have to worried for it. Thanks