Hi. I have recently started having severe pain in the middle of my forehead as soon as I get outside in the sun. The pain will be so severe it's like my whole head starts to burn on the inside. I deliver mail so I am in a car all day and just started wearing SPF a few months ago, about when this started. I can go to hang clothes on the line, and if the sun is out I have to go inside because it hurts so bad. Any idea what this could be?