You are just that unique.
Doctors have a clue as they've managed to complete medical school. But medical school can't teach every doctor about every unique person. They're taught all the basics that cover almost everyone, but it's impossible for a doctor to know that you may have some strange sensory side effect as a result of taking a common, safe, OTC cough syrup/antihistamine/sleep-aid.
Countless people consume Benadryl every day for it's medicinal properties, and yours is the very first I've ever heard of having that particular adverse reaction. Heck, Benadryl is a medicine usually consumed to counter adverse reactions from other things!
You are just that unique & while it may be frustrating, you have to accept that and that doctors do the best they can for their patients based on what they know. Your doctor could not have possibly known that Benadryl might cause you some strange never before heard of reaction & thus if you're upset with your doctor, your anger is misguided. Instead, just be happy that you found out, safely, that Benadryl isn't a medicine you want to take and move on with your life.
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No
for supporting trump. Because doing so is deplorable.