i recently have developed severe neck/shoulder/head pain. the pain seems to start in my right shoulder,along the top, it radiates up into my head, along the right side centered between the back of my head and my right ear. it radiates the other way, down my arm to the elbow. when I exercise by walking, the right arm almost seems to go numb.. I do not have a noticeable shortness of breath. I sometimes also get a numbing sensation down my right leg. any ideas?