(CNN) — Amber Vinson says she followed all the rules when caring for an Ebola patient. So how did the Texas nurse contract the deadly virus?

“I have no idea,” she told CNN. “I go through it almost daily in my mind: what happened, what went wrong. Because I was covered completely every time. I followed the CDC protocol. … I never strayed. It is a mystery to me.”

Vinson, who was declared Ebola-free last week after treatment at Emory University Hospital in Atlanta, spoke with CNN’s Don Lemon in an exclusive interview that aired Thursday. She described her experience fighting the deadly virus and fired back at critics who said she should never have boarded commercial flights after treating an Ebola patient.

“I’m a nurse. I care. I care for me, I would not put myself in danger. First, I would not take Ebola to my family and my best girlfriends. I would not endanger families across the nation, potentially exposing them to anything,” she said. “I had no symptoms. There was no way, at that time — I could not transmit it.”

The 29-year-old nurse choked up thinking of the harsh reactions of some people after they learned she had Ebola.

“It’s just not me,” she said. “All I do is care. All I want to do is help. I would never try to hurt anyone.”

‘I did what I was supposed to do’

Shortly after Vinson’s diagnosis, CDC Director Dr. Tom Frieden told reporters that she shouldn’t have taken the flights.

“The CDC guidance in this setting outlines the need for what is called controlled movement. That can include a charter plane, a car, but it does not include public transport,” the Centers for Disease Control and Prevention director told reporters at the time. “We will from this moment forward ensure that no other individual who is being monitored for exposure undergoes travel in any way other than controlled movement.”

Vinson said she felt like Frieden blamed her without any basis.

“I did what I was supposed to do, and now you’re saying I should not have flown,” she said. “You know, I checked multiple times before I even left Dallas to see if it was OK to go.”

And when her return flight from Cleveland to Dallas got repeatedly delayed, Vinson said she checked her temperature multiple times and reported it to the Texas Health Department. Then her contact there would speak with the CDC.

“She would tell me if i was OK to go or not,” Vinson said. “And I got the OK every single time.”

‘It’s a struggle’

Vinson’s diagnosis came amid a wave of national concern about the possible spread of Ebola in the United States, especially after it became known she had flown on two commercial flights after treating Duncan. She became the second person known to have contracted Ebola in the United States, and the second nurse from Texas Health Presbyterian Hospital Dallas to get the virus after caring for an Ebola patient.

Learning that her colleague, nurse Nina Pham, had contracted Ebola was a shock, Vinson said.

“My heart dropped,” Vinson said. “I was afraid for myself. My first thought was, Nina is a great nurse. I know her nursing. She follows rules and protocol as closely as I do. If this happened to her, it can happen to me. It rocked my world.”

Several days later, Vinson was diagnosed with Ebola after returning to Dallas from a trip to visit family in Ohio, where she was planning her wedding.

Days after being inside a bridal shop, she was isolated in a hospital, fending off the virus. It wasn’t an easy battle, Vinson said.

“It takes so much out of you. It really does. It is very draining. And even now … walking a short distance, I get short of breath,” she said.

There were several particularly rough days, she said.

“You’ve got to force yourself to get up, and forcing yourself takes a lot out of you, too,” she said. “It’s a struggle. You’re fighting for your life.”

Mom: ‘I just wanted to be there’

For Vinson’s family, it was also a harrowing ordeal.

Like television viewers across America, Debra Berry stared at a TV screen and saw her daughter walking from an ambulance into the airplane that would take her from Dallas to Atlanta for treatment.

It was a devastating sight for Berry, who was quarantined in Dallas and so couldn’t be with her daughter.

“I wouldn’t have cared if she had triple Ebola. I’m her mother. Give it to me. Wrap me up in Hefty bags,” she said. “I just wanted to be there. Because I knew in my gut that she was alone.”

Hearing remarks people made about her daughter didn’t help.

“I think they could have used the science to guide the situation, rather than make the comments they they did,” Berry said.

Even now, she said, “people just aren’t listening.”

“I want them to hear that my daughter is a hero,” she said.

Vinson’s fiance, Derrick Markray, said the intense media spotlight has been difficult.

“It’s not like she’s an entertainer who was looking for fame,” he said. “It found her.”

In the interview with Lemon, he described the agony of the first days after Vinson’s diagnosis.

He feared the worst, realizing that if Vinson died, her remains would be discarded as hazardous waste; there wouldn’t even be an urn at her funeral.

“The reality of it all just really set in, the gravity of it,” he said.

He wondered, “Can our system really handle this?”

Ready to rebuild

Vinson survived the deadly virus. Doctors can’t say for sure exactly what saved her, though they say her young age and how quickly she received treatment were likely factors.

Going forward, Vinson said it’s clear that more planning is necessary for U.S. hospitals to better handle Ebola.

“We weren’t the best prepared,” she said. “We did not have extensive training. We did not have a level of feeling comfortable with putting on and taking off the protective equipment. We didn’t have the time to practice it. There was not a lot of education done beforehand.”

That, she said, is a lesson that hospitals need to take seriously.

“Everyone needs training,” Vinson said. “Health care providers need to feel comfortable. They need to feel like they’re protected so they can provide the best care.”

Vinson said nursing remains her passion, but she doesn’t know when she’ll be suiting up in scrubs again.

“Right now I have to take care of me,” she said.

“It’s taken weeks. I feel like I gain a little bit of strength every day,” she said. “But I know me, and I’m not at the position right now where I feel comfortable providing care.”

For the 29-year-old nurse, it’s also time to get her life back on track.

After her diagnosis with Ebola, cleanup crews destroyed her engagement ring and the wedding binder she used to plan her upcoming nuptials.

“We’ve got to rebuild,” she said.

And if anyone else contracts Ebola, she’s ready to step in — this time by donating blood to help in their treatment.

“Are you going to give plasma?” Lemon asked her.

“Absolutely,” Vinson said, “as soon as I am able to do so.”