One year after the violent attack on Capitol Hill by a mob seeking to overturn the 2020 presidential election results, many House lawmakers are still struggling to wrap their heads around the brutality of that day. 

"It's really hard to believe it because it still feels like it was just yesterday. All of the memories feel just as fresh and raw. The enormity of what we faced – our lives, our democracy, the fragility of all of that, it’s still hard to process," Rep. Pramila Jayapal, a Democrat from Washington state, told ABC News during a sit-down interview in late December. 

The chaos and violence unfolded over the course of a few hours on that fateful day. But for many who were there, including lawmakers, legislative aides, members of the press, and Capitol Police officers -- the trauma still lingers. 

ABC News sat down for an in-depth interview with several House Democrats who were in the gallery of the House chamber last year on January 6, 2021. They experienced firsthand the terror as rioters attempted to breach the chamber. 

"I never thought I would be in the Capitol of the United States of America and be attacked by other Americans," Rep. Mikie Sherrill, D-N.J., told ABC News. 

The images and sounds of that day are unforgettable: the gunfire, shattered glass, a noose at the foot of the Capitol’s sprawling green lawn. 

Trump supporters -- brandishing flags, poles, and other makeshift weapons, storming the venerated building, an American symbol of democracy. 

The group of lawmakers, trapped above the House chamber in the gallery, were at one point instructed to reach for gas masks stored under their seats. 

"Initially for me it was just, how do you get out? I wasn't even thinking fear. I mean, we didn't even know how to open the gas masks in the gallery," Rep. Lisa Blunt Rochester, D-Del., said. 

Rep. Blunt Rochester said she knelt in prayer as the violence erupted just outside the chamber, which she said evoked a flood of emotions and imagery. 

"When we prayed, that made me feel back to the word: faith. Like all in that balcony, in that gallery, I could just feel every ancestor. I could feel slavery, Jim Crow, everything, all of the bad things that have to wake you up to what the reality is," Blunt Rochester said. 

Rep. Jason Crow, a former U.S. Army Ranger, took cover as his military training and instincts kicked in. 

"I will admit that I still harbor feelings of anger and resentment," Crow, a Democrat from Colorado, said.  

"I never thought that I would be thrust back into that mindset again. But for a brief moment there, I snapped back in to that 'Jason Crow, Army Ranger' mindset and was preparing myself to potentially have to take life again, to protect us and get out. And that wasn't a great place to be in." 

Jayapal admitted she has struggled to return to the place of such sorrow. She has not returned to the gallery where she was seated in the chamber that day. 

"I think about it all the time. And every time I get an alert on my phone … I feel my heart starting to race a little bit more, more anxiety. I haven’t gone back to the gallery since that day. I haven’t. That night they told us to go back to the same place that we had been, and I was like, I'm not going back," Jayapal said. 

"It was traumatic. It was returning to a place of trauma," Jayapal added. 

The group of Democrats together in the gallery that day by chance, now bonded forever by the trauma. 

"Nobody can go through an experience like that experience trauma, not having some impact," Crow said. "And getting help is not a sign of weakness. It's a sign of strength." 

They have stayed in touch using a group text message to communicate their thoughts and feelings, and also holding group therapy sessions with a psychologist. 

"It's been a blessing in a way, far beyond January 6. I know as a group, it’s made us more resolute, more compassionate, and stronger," Rep. Dean Phillips, D-Minn., said. 

Phillips still has the gas mask he used one year ago. 

"To bear witness," Phillips explained. "This is going to go with me wherever I end up as long as I am here in this job, on Earth, because this moment is seared into my memory and it’s my responsibility." 

Lawmakers have said one of the most challenging aspects of their jobs following the riot is figuring out a way to work with some of their Republican colleagues who voted to overturn the presidential election results and downplay the violence and terror of that day. 

"I’d say some of those colleagues of ours who want to pretend that it never happened. Here you had this incredibly vitriolic, traumatic experience and yet we serve with folks who want to pretend it was a tourist visit. And that's tough, that's a tough pill to swallow," Crow said. 

The insurrection has only deepened the fraught partisan divides, eroding trust between members who were caught in the crosshairs of the violence. 

Freshman Republican Troy Nehls came face to face with the mob and condemned the violent acts. 

"The center doors started to shake violently … And then the glass shattered … I saw a young man and he was looking at me and I was looking at him and. And he said, 'You're from Texas, you should be with us,' … And I told him, this was un-American what you're doing,” Nehls told ABC News in an interview. 

Hours later, when lawmakers returned to the chamber to certify the election results, he was one of 147 Republicans who voted against it. 

One year later, the feelings are still raw. 

The pandemic, together with reverberations from the Capitol riot, have led more people on Capitol Hill to seek help. 

In 2021, the Congressional Office of Employee Assistance handled 12,200 interactions with employees, managers, and members of the Hill - including 5,600 counseling sessions. 

That's roughly four times the number of interactions the office handles in a given year, pre-pandemic. 

The office has also conducted 40 trauma support briefings, according to a spokesman for the office. 

Many who were on the Capitol that day are still shaken by the attack, struggling to cope with the trauma. 

"I personally haven't gone through anything as traumatic as that – that has been my most traumatic experience," Leah Han, who works in House Speaker Nancy Pelosi’s office, told ABC News in an interview. 

Leah Han, and her colleague Nathaniel Holmes, who also works in Pelosi’s office, were just steps from the House Chamber on Jan. 6 when the riot erupted. 

"I never really dealt with anxiety before, but I now have anxiety," Holmes told ABC News. 

"We started hearing people in the building. It was no longer just these chanting and shouts from outside. You could hear people in the hallways … It just seemed as if someone's capable of breaking in the Capitol building, what else are they capable of?" he said. 

Pelosi staff members grabbed what they could and raced to the closest conference room, barricading themselves inside – no members of Pelosi’s security detail in sight. 

Han said she struggles when imagining what could have happened had they not had a secure place to hide. 

"I've thought about that a lot. What would they have done if they had found us? Were they going to kill us? Were they going to torture us? Were they going to rape me? I don't know. I just don't know. You were thinking about everything, all the possibilities. I mean, I couldn't help but try to prepare myself," Han said. 

Han and Holmes said they starkly remember the mob pounding at the conference room door as rioters desperately searched for the speaker. 

"Where are you, Nancy? Nancy, where are you? Oh, Nancy,” the rioters chanted as they rummaged through nearby offices. 

Pelosi’s staff, including Holmes and Han, hid under a table inside the conference room where they were barricaded. 

"I thought I was going to die. I mean, I just remember I kept thinking, 'This can't be happening. This can’t be happening to me,'" Holmes said. 

Holmes said he still can’t "unhear" the sound of the rioters pounding on the door. 

While the initial shock of the attack has worn off, an unanticipated grief remains that even time can’t seem to shake. 

Yet, despite the trauma, they are resilient. 

"I don’t think we can be the same. We are a collection, our building is a collection of all the things that happened to us, in us, and so … courage begets courage," Jayapal said. 

"I don't know if I can ever be the same, but it doesn't necessarily have to always be defined by that," Holmes said. "I hope it's not defined by that … I don't know if it'll be the same, but hopefully it can be better." 

1 year after Jan. 6, House lawmakers tell of trauma, grief and resilience 
January 6, 2022 – ABC News 
By Rachel Scott, Mariam Khan, and Benjamin Siegel