What Causes Pain In Head Radiating To Shoulders And Back?

hello! i am a student in some college and iam suffering from a disease from the last 8 month or so! i am really worried. the problem is that the pain starts from the back of my head and then it moves to many parts of my body like my shoulders starts to burn as if someone has put lots of load on my shoulders than it the pain moves into my chest and then it moves in my spinal cord. its very painfull. So can u plz tell me that from what type of disease i am suffuring from?? and what shall i do to get rid of it!