Storm clouds gathered in Miami on Saturday, the day before Hurricane Irma made landfall.

HOLLYWOOD, Fla. — Floridians stared at televisions as meteorologists pointed to a menacing storm marching toward their shores — along with scenes of hurricane-battered Houston. They heard Gov. Rick Scott repeatedly order families to get out of vulnerable areas. They holed up with strangers in shelters, fretting about what this powerful storm could do — would do — to their homes. They waited for the storm to pass, then jumped on packed highways to return to the unknown.

Almost from the first Hurricane Irma forecast, Floridians have been in an emotional cone of uncertainty, even those who were hardened by hurricanes past.

“This has been one of the most anxiety-inducing storms that I can remember,” said Meggen Sixbey, associate director and clinical associate professor of University of Florida’s Counseling and Wellness Center. “The images comparing the size of Hurricane Andrew to Hurricane Irma and the length of time it took to get here made it even worse. In waiting for the storm, you are talking about the fear of the future and when it’s over, you are talking about the fear of what you are returning to, if anything.”

In some ways, watching the sheer power and scale of Irma — wider than Florida itself, at times toggling between Category 4 and Category 5 in strength — forced a series of stressful but necessary routines.

People rode out Hurricane Irma in a hotel in Miami on Sunday.

“People are worn down by the process of awaiting a storm, the process of fighting gas lines, the process of evacuating, staying with friends or family,” said Ms. Sixbey, who worked to give psychological first aid to survivors and emergency medical workers after Hurricanes Charlie and Katrina. “After a disaster or major trauma, the first three emotions that people experience are shock, denial and disbelief.”

By the time Irma crossed the state border as a tropical storm, it had made two landfalls in Florida, forced one of the largest evacuations in American history and left people weary and worried.

People like Kathlien Neizer, 59, who tallied her remaining cigarettes on Tuesday. Just four left. And that was the least of her troubles.

The day before, the monstrous storm had sent floodwaters pouring in the windows of the mobile home she shares with her partner, Jonathan Sevigny, 59, who recently had triple-bypass surgery. The couple were rescued as the waters rose — leaving Ms. Neizer so harried that when she finally walked into the hurricane shelter, she had to take blood-pressure medication. As she sat on a hard plastic chair outside the shelter, there were so many worries, big and small, that she barely knew where to start.

Heidi Bizette and her daughter Everly Giran at a gas station in Cecil, Ga. They evacuated their home in Winter Springs, Fla., because of hte storm.

“The water’s down a lot, but everything in it is totally…