What Causes Headaches, Sore Throat And Discomfort In Neck?

For the past month I've been experiencing headaches unlike ones I've ever had. They're usually on the right side of my head, as well as near my right ear and in the lower back of my head towards my neck. All of a sudden, I have a sore throat, difficulty swallowing, persistent headaches, and a lot of pain and discomfort in the back of my neck as well as both right and left sides of my neck. what could this be?