I have a headache which at first I thought was caffeine withdrawal. It started three days ago. Then two days ago I woke up with a stiff neck, and the headache came back, a constant feeling of pressure. I have taken Advil, and Excedrine. I have tried a heating pad. And icy hot. I get only temporary relief (30 minutes tops) The pain is concentrated in my neck area to left shoulder blade and upper left arm