Diana Litzenberg lies in a hospital bed at University Medical Center in Las Vegas on Thursday. Litzenberg was injured when she was trampled after a gunman began firing at a music festival Sunday. (John Locher/AP)

Diana Litzenberg was hiding under bleachers, clawing dirt, as bullets were bouncing around her on the Las Vegas Strip nearly one week ago.

When she saw a woman who had been shot staggering alone, Litzenberg stood up to try to help. Then a panicked man plowed into her, face to face, tossing her onto her back.

Litzenberg regained consciousness a few hours later in the trauma unit at University Medical Center of Southern Nevada. She was diagnosed with a severe spinal cord injury that resulted in partial paralysis to her left side, possibly the result of being trampled by the crowd fleeing the gunfire.

Now, like hundreds of others injured in a gunman's attack on a country music festival on Sunday, Litzenberg wonders what it will take to regain her health, strength and emotional stability and whether her journey back to routine can even be measured in time.

"I am just going to push forward, and hopefully everything will be okay," Litzenberg said as she broke down during an interview from her hospital bed this week. "I want to just get back to the same happy person I was, and I don't feel very happy right now."

[‘Something we would see in a war zone’: Military surgeons on the wounds they treated in Las Vegas]

In addition to the 58 people killed in the massacre, Stephen Paddock's attack left nearly 500 others with wounds ranging from burns left by passing bullets to debilitating internal injuries that threaten lifelong paralysis. The overwhelming majority of victims suffered gunshot wounds, Las Vegas doctors say, while dozens of others were injured in the frenzied stampede that ensued.

Most of the survivors — including people who had traveled to the Las Vegas festival from across the country — have been treated and released from eight area hospitals, returning to their homes, rehabilitation centers or hometown hospitals to continue their recovery. That has left the most debilitating cases behind. As of Friday evening, 78 patients remained hospitalized, including 34 in critical condition.

They are the ones facing the most precarious journey, attempting to recover from crippling injuries while their families juggle mounting medical bills and the emotional and financial toll of traveling from out of town to remain bedside.

For many, long after they leave Las Vegas, the recovery process will be grueling — measured in their ability to slowly regain basic human behaviors such as eating, walking and comfortably sleeping.

Natalie Vanderstay, for example, was shot in the stomach during the attack. But on Thursday evening, her family became more confident of her eventual recovery after she went to the bathroom on her own for the first time since the shooting.

"Her organs started working again," said her relieved sister, Rachelle Vanderstay, adding her sister hopes to soon return to Los Angeles for additional treatment closer to home.

Jeffrey Murawsky, chief medical officer of Sunrise Hospital and Medical Center, said gunshot victims' ability to make a full recovery depends on where the bullet entered, how it bounced around the body, and a patient's overall health before they suffered the injury.

[Invisible wounds of Las Vegas shooting could affect tens of thousands]

In best-case scenarios, patients who were only grazed by a bullet, as appeared to be the case for more than 100 Las Vegas victims, Murawsky said the injury is not much different from a laceration or mild burn.

"It looks like a cut, but it's actually from the bullet, and you just bandage it and arrange for them to see a doctor in a clinic the next day," Murawsky said.

A bullet that lodges in body fat without striking nerves, arteries, organs or the digestive tract can also heal relatively quickly. Many of those patients were also released from hospitals within days, if not hours.

But with Paddock firing high-caliber ammunition from military-style rifles, dozens of patients suffered severe damage to tissue and organs. They will face extensive recoveries, but Murawsky said many of them will also eventually make a full recovery.

"Many of our chest wounds were lung injuries, so the bullet went in and out through a lung, and your lungs are pretty resilient, especially if you are young," Murawsky said. "You won't work for a couple weeks, but you are going to go back after that, and you will kind of get your wind back over time."

But the most critically wounded patients may never make a full recovery, especially if they suffered trauma to their head, bowels or spine.

Some patients will suffer from lifelong phantom pains.

"To heal the nerves in the pelvis are typically bad, and that can be very debilitating," said Faran Bokhari, chief of trauma and burn surgery at Cook County Health and Hospitals System in Chicago. "The nerve will die, but part of the nerve still attached to you — a bullet goes through, cuts off part of it — that part that is still attached to you sends false signals to the brain."

Doctors have told Litzenberg, 52, that she will need weeks or months of rehabilitation to see whether her muscles and nerves can respond enough for her mobility and motor skills to return.

Litzenberg, from Orange County, Calif., works for a property management company while her husband works as an HVAC technician.

She does not have health insurance.

[As the wounded kept coming, hospitals dealt with injuries rarely seen in the U.S.]

A Las Vegas-area rehabilitation center has offered to pay the cost of her upcoming treatment, but the family is still waiting to get the bill for her time this week at University Medical Center. The family has also set up a GoFundMe account.

Even with donations, the Litzenberg family is preparing for years of financial hardship.

Although her 22-year-old daughter and her sister have been camped out at her bedside, she said her husband had to stay behind in California to make sure the family can keep "paying the bills."

Nicole Rapp, Litzenberg's daughter, said the impact of Paddock's rampage inflicts cascading turmoil on the victims' relatives.

Rapp, a merchandising manager for Target, must also juggle her job in California with trips to Las Vegas to help her mother.

"As a daughter, to go through this, it's just heartbreaking, and I sobbed three times just today," Rapp said in an interview Friday. "I am going to be dealing with it, making sure she's all right, getting her back to California . . . and there are so many people dealing with this."

Litzenberg also worries about her ability to recover emotionally.

"I had seven nightmares last night of being shot — it's in your mind," Litzenberg said Thursday evening. "I keep seeing the same girl going down. I keep seeing the lights. I keep hearing the banging. I keep hearing the sirens — it's horrifying, and it's horrifying for everybody."

Bokhari cautions that mental-health treatment can be one of the most overlooked phases of trauma recovery. Many patients will suffer from spontaneous tearing, fright and overall feelings of hopelessness.

"I think we all like to think we know what it feels like, because we've watched a lot of movies, but in talking to people who have actually had it done to them, it's much deeper than a non-injured patient would think," said Bokhari, adding that a good social support system is critical in overcoming the psychological problems.

Maj. Charles H. Chesnut III, an Air Force surgeon who tended to patients at University Medical Center after the shooting, said many injured in this tragedy are already stressing over how they will return to their everyday routines.

One patient with a gunshot wound to the abdomen asked whether she would ever be able to run a marathon again, even as doctors had just inserted a chest tube to control bleeding and open her airways.

"She was scared, but in the face of all of this, that is what was really important to her life," Chesnut said. "But that is our goal — not just to save their life, but getting them back to things they are used to doing before."

Generally, Chesnut said it's possible for a gunshot victim to be doing minimal walking and exercising after four to six weeks of rest. From there, most of a patient's strength will continue to accelerate, perhaps even to the point of running a marathon.

But Chesnut said both the victims and their support network must remain determined, a point not lost on Litzenberg.

"I am strong. I know I am. So I will get through this," she said. "But for all those families out there that are not strong, it's a tough situation."