Hi, Thank you very much for your question. It is quite difficult to say anything without being able to recommend you for clinical examination and MRI investigation. A classic brain tumor headache can be characterized by early morning pain, dull and aching, nausea, vomiting, and headache can wake you up in night. Additionally, this tumor may be accompanied by neurological signs & symptoms such as seizures, personality disorder or weakness. Another possibility in your case could be a brain stroke and this occurs when the blood supply to the brain is disturbed due to a clot and person may experience severe headache, confusion, loss of vision & facial muscles weakness. Although the stroke probability in your case is less, I would recommend you to see a neurologist who can evaluate the details of your case and could better determine the insight of your situation. If your neurologist identifies any “red flags” he or she would like to refer you to a neurosurgeon much sooner. Hope this helps.
It does not sound at all like a tumor- look at "ice pick" headache or cluster headache. Or maybe occipital neuralgia.