Your headache, puffy red eyes, pain behind eye, light sensitivity, & clogged up head are symptoms of a sinus infection. It might be caused by die-off and/or the toxins they release.
To decongest your sinuses & reduce the inflammed tissue, suggest you take an OTC sinus/nasal decongestant & pain reliever med. Check labels for those ingredients. Skip those containing antihistamines.
Recommend you stop taking Benadryl. It's not a decongestant. It's an oral antihistamine for runny nose, itchy body rashes, & allergic reactions to bug bites & other types of meds. Large doses are too drying on congested/swollen sinus tissues & can cause headaches.
I suffer from chronic sinusitis & have tried a zillion products. We're all different, so what works for one person may not for another. This product provides the most effective relief for me:
"Equate Sinus Congestion & Pain": Dosage is 2 tablets. Each tablet contains Acetaminophen (aka Tylenol) 325mg, Guaifenesin 200mg, & Phenylephrine HCl 5mg. Available at Wal-Mart or check drugstores for store-brand equivalent.
Also suggest you rub Vicks VapoRub on painful areas....frontal sinuses, around nose, dab in front of each nostril, & back of eyelids. The fumes will cause your eyes to water but so worth it for the penetrating pain relief you get.
I find that taking a 1-2hr catnap as a chaser to the tabs & Vicks is the magic bullet for sinus relief! (meow meow)