Some thoughts I had while reading your list of symtoms. It certainly sounds by your history and physical findings as of late that your ear, nose, and sinuses are congested. This could be from allergies, or from something called "vasomotor rhinitis", which is a bit more elusive in its causes and treatment. Chronic sinusitis is also a possibility. Typically vasomotor rhinitis can be treated with a nasal steroid much like allergic rhinitis but often requires the addition of a second type of nasal spray. Both vasomotor and chronic sinusitis respond to good nasal hygiene, including nasal saline spray or sinus lavage, dust control in the home, good diet (high in omega 3 fatty acids), exercise, and stress reduction. Allergy shots typically are not very helpful for airborne allergies (dust, pollen, mold spores, etc). I would also address sleep and stress particularly as it relates to your anxiety, as this obviously can make the "brain fog" much worse.
"Allergy shots typically are not very helpful for airborne allergies (dust, pollen, mold spores, etc)."
I discovered that personally ! I've heard about sublingual therapy, but understand that it isn't available in the U.S. yet. I have tried homeopathy for my allergies and was surprised to find out that it does help with my symptoms.
I agree with the workup thus far, including the antibiotics courses and CT scan.
Allergy testing can be considered, as well as optimizing treatment for chronic rhinitis. This can include further evaluation with a sinus CT scan, as well as nasal steroid sprays.
A referral to a neurologist can be considered. Further imaging with an MRI can be done to exclude pathology in the brain. If seizures are considered (which can lead to a "fog"), an EEG can be discussed.
These options can be discussed with your personal physician.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.