My name isXXXXX you for using Just Answer. I am happy to help you with your concern.
Having this significant of a headache for 3 days is a bit worrisome. You may need to have a MRI of your brain to make sure you do not have something abnormal going on like an aneurysm, tumor, cyst, etc. If the MRI comes back normal then your doctor can give you an injection of pain medication and you should start feeling better within an hour or so. Or if they feel it is sinus related and you have a sinus infection, antibiotics will be given.
If you don't feel like a MRI is warranted, then other things you can try are alternating extra strength Tylenol with ibuprofen, increase your caffeine intake, use a cool compress on your forehead, if you can limit your time on the computer. If you feel this may be sinus related, try taking a sinus medicine like Sudafed or use a nettie pot. Also staying in darker rooms can help as well.
The cause of your headache may also be from eye strain due to computer use. If you have not recently had your eyes examined then you should have this done soon. You may need glasses to wear while on the computer. They make a product that is applied to the lenses that reduces glare.
I hope you feel better soon. If you have any further questions please let me know. Thanks again for using Just Answer. Have a nice day.