I like your ideas of carrying some Tylenol, Benedryl, first aid kit, Glock 30 and maybe a second magazine of ammo.

I already carry tools, patch kit, paper towels, air pump, water, cell phone, debit card, small cash and even a Leatherman tool. I also have a vinyl shower curtain, some nylon parachute cord (for making a shelter in case of heavy rain storm) and several packets of honey that I got at a KFC, for quick energy boost if needed.