First of all, I am sorry to hear that you have been having problems with sinusitis, and that you are still dealing with forehead pressure despite three weeks of antibiotics. This isn't the easiest question to answer in the setting of a Q/A forum because I am not able to interact with you and ask important questions about your history, and what work-up has been done already, what antibiotics, etc. Also I am not sure exactly who you saw already that diagnosed you with a sinus infection after developing drooping of your eyelids. Typically in the ENT's office sinusitis is diagnosed by taking a thorough history (sinus pressure/pain/drainage for more than 2 weeks...because most viruses last 7-10 days) and performing a thorough exam (including nasal endoscopy to look for inflammation and/or mucopurulence draining from the sinuses). Also commonly a CT scan
is done of the sinuses without contrast to look for opacification of the sinuses (which can mean fluid or tissue is filling
the sinuses), bony change (like thickening from chronic rhinosinusitis, or erosion from a tumor), or an air-fluid level which is seen in acute infections. All of this information is very important to an ENT. I would definitely recommend that you make an appointment to be seen by an ENT to be evaluated, and they will likely perform some of, if not all of the above procedures in working up your sinus disease. I hope that this is helpful.