While many of these things can, and might well happen, the chance of all happening at once, and over a wide enough area of the Country or World to really matter, is remote.
Good points to remember are to have what you and yours needs for at least a few weeks. No one should be dependent on the Government or the kindness of strangers in any time frame short of a month.
Second, you should have long ago figured out only how, but WHEN you and yours are going to leave a built up area.
Third, remember that no plan survives first contact with adversity. Have a back up plan, and a back up for that one.

If the entire country is affected with all of the most dire scenarios, then all bets are off, and serendipity might well play as important as part in your survival as planning.