Hello,
Thanks for posting your query.
Severe headache in the occipital region can be due to minor problems like migraine , occipital neuralgia, anxiety or significant causes like subarachnoid hemorrhage in brain, meningitis , hypertension etc.
There is no single analgesic which can be termed as best for headache . Aspirin is not the preferred analgesic rather acetaminophen or ibuprofen in prescription doses are preferred . Remember pain killers are just temporary relievers of pain and if the exact cause of the headache is unknown they can delay specific treatment and worsen the prognosis.
Also ,they are not without sideeffects and self medication with over the counter analgesics is not recommended .
As of now since you have been sufferring from last five days without much relief from over the counter analgesics it is advisable that you please consult your physician for evaluation and appropriate management of your headache .
Though you have got your vision assessed , in addition to it a physical examination including blood pressure measurement , neck rigidity and neurological examination are advisable for confirming the cause.
Sometimes in the worse scenario , a computed tomography (CT)scanof brain might be required if examination is suggestive of a significant cause.
Please do not panic , it's most likely not a serious cause considering you have no medical illness or associated symptoms yet it's advisable to consult a doctor to be on the safer side.
Hope I have answered your query.
I'll be available for any follow up queries .
Regards

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