It’s not panic. The day after tomorrow, there will be over a thousand cases and about fifty dead. It's going to go up for a while.
Wearing a mask is pretty useless. It only makes sense if you already have it and don’t want to sneeze or cough contagion out. It won’t help much against incoming.
If you have a good coverage, then incoming droplets or particles will get stopped by the mask, and you’ll likely touch the surface of the mask multiple times a day in adjusting it, apart from removing it to dispose of.
This doesn’t matter if you already have the contagion. You can’t catch it twice.
But if you have it, it’s a courtesy not to sneeze or cough out droplets into the air that others are breathing.