To talk seriously, I think the worst thing that could happen would be an economical crash. There's no need to fear nuclear war (either it will be much more limited than you'd expect, or you'd be volatilised in a matter of seconds, in both cases it's better than what's shown in movies), no need to fear huge epidemics (not happening with modern medicine in a developed country, unless we have to pay for it upfront of course), but fear the economical crash.
It's what made my family emigrate in the early 90s (we were lucky to have some savings in gold, or we'd have been forced to stay and endure it) and, more relevant for the USA due to ethnic differenced, what provoked the bloody end of Yugoslavia. In both cases, it means no wages, no edible food in shops, no rule of law, no health system unless you bring imported medicine to a doctor you know, and in the case of Yugoslavia, you add a topping of ethnic warfare on top of that ; which isn't too much of an unrealistic scenario, given the fun events at Charlottesville recently. Even the lightest, softest version you could face is what happened to Greece in 2008, with no jobs, mass emigration, political violence in the streets and HIV and drugs epidemics. And it has happened a lot of times in recent history. All of those countries got better now, yes, even Greece is back on track and is hoping to thrive again soon, but they still suffered for a couple years.
Ideally, you'd get yourself something like
this five years before the storm, grow fruits, vegetables and have chickens and goats for meat and dairy, stock up on guns and ammo and buy solar panels for your house, but I somehow think that not everyone can do it.
Then, according to survivors of the Sarajevo siege, the best way to survive would be to form "alliances" between families living next to each other, putting together 20-30 people including 2 thirds of working age adults, have guns and ammo (not the badass tactical kind, it'll get you killed because some local warlord wants a cool looking carry piece), have medicine (lots of it), and learn how to go to the toilet with a shovel and a patch of grass behind the house. Such an event has sadly no easy or cool way out, unless you can buy the aforementioned island or at least go abroad and buy a house there.