I suffer from migraine and tension headaches, and to me it sounds like a tension headache, but I am not a doctor. I would suggest you go see a neurologist. Best of luck to you, Will keep you in my prayers.
Yeah... I would go back to the doctor for sure. Go to an Urgent Care Centre... they deal with headaches better than the ER... sometimes ERs are too busy to deal with headaches once they have ruled out an aneurysm or a stroke... so, I would suggest going to an Urgent Care Centre. If you don't have an Urgent Care Centre in your area, go to your family doctor ASAP and like NTC1028 said, get a referral to a neurologist too.