I've lived through a few hurricanes, been in the woods for a days at a time, have had broken bones, been held up at gunpoint...
Staying calm is vitally important. The best thing to help in staying calm in having experience and knowledge. When confronted with new situations it's much more stressful because you don't know what to do next.
So preparation is key. It might be as simple as stocking up on a few items. Tarps, canned goods, *water*, first aid kits, etc. come in handy. There are also some other less obvious things... A GPS unit is so very helpful... When Hurricane Andrew stopped by it took away all the street signs. I remember driving to check on a relative who lived less than 5 miles away. Without street signs I could not quickly find a house I'd visited dozens of times before... You know what I missed too? Toothpaste. And baby wipes. We were able to flush the toilet, but showering was risky because of possible breaks in the water lines.
Having a plan is helpful. It could be as simple as knowing where the exits in your house are. Where is the closest shelter? If your car is un-driveable (blocked or destroyed), can you walk to that shelter with the 6 days worth of equipment? The sleeping bag and the 2-burner propane stove seems a lot less necessary when you need to carry it 10 miles on foot.
Do you have copies of your paperwork? Some people scan deeds, insurance papers, contracts, etc.. onto a USB stick. Others put them in a fire safe. If you have to leave your home, can you carry that safe along with 200lbs of other equipment?
Do you know how to set a broken bone? Can you use wound gel? What happens if you get punctured by a rusty nail?
We can go on for hours about the things we need. Firearms? Will they help set your broken leg? I'm not discounting their value, but carting around an AR-15 and that heavy-ass ammo is not too likely if you have to move.
And don't forget your towel.