I feel like my head is going to implode! When should I go to the doctor?

I've had a cold for three days, but since yesterday, the main problem is congestion. My forehead hurts from sinuses, and my nose (only one nostril at a time) is so stuffy. My ears...oh man. I've always had problems with my ears. With this cold, they have been so plugged. Just now, I blew my nose, and my left ear popped, and it hurt so bad. Now, I get earaches all the time, but this was unbearable. It eventually subsided after a few minutes when the pressure equalized, but it still hurts. My right ear, however, has become even more stuffy. In general, my whole head feels pressurized and I feel like it's going to implode on itself. When should I go to a doctor?