“Free Solo” scared the crap out of me. I can’t think of any other movie that frightened me more than this one, which won an Oscar a week ago and aired — commercial-free — on the National Geographic Channel on Sunday at 7 p.m.

I’m a complete coward when it comes to horror films, though I can at least tell myself that horror films aren’t real. “Free Solo,” on the other hand, was all too real to someone like me, who is terrified of heights. It chronicles Alex Honnold’s June 3, 2017, ascent of El Capitan, the sheer rock formation at Yosemite National Park in California.

“Free Solo” means climbing without ropes or any other device. Just Honnold using his hands and feet to climb nearly 3,000 feet.

If he’d slipped at 100 feet, he’d be dead. If he’d slipped at 2,900 feet, he’d really be dead. It’s horrifying.

Yes, I know he made it. Honnold recently appeared before TV critics to talk about the film, which won the Academy Award as outstanding documentary for filmmakers Elizabeth Chai Vasarhelyi and Jimmy Chin.

“Free Solo” isn’t just about the climb, it’s about Honnold. And he’s … unusual. Determined. Focused. A brilliant climber. But awkward. Largely lacking in people skills. And he’s in the midst of a new and serious romance with his girlfriend, Sanni McCandless, who features prominently in the film.

“It’s not just a fairy tale romance, it has really real moments where there are high highs, and low lows, and hard conversations,” McCandless told TV critics. “And I think people relate to that.”

A lot of people who know a whole lot more about rock climbing than I do thought that free climbing on El Capitan was crazy. “People who really know exactly what he’s doing are freaked out,” a fellow climber says in the film.

It was incredibly stressful on those involved in making the documentary — including the camera operators who climbed El Capitan (using ropes) and positioned themselves to capture Honnold’s climb.

“If you watch the whole film, I think it’s pretty obvious,” said cinematographer Mikey Schaefer. “You know, the emotional toll it took on me. ... It was really hard on me. I mean, just being so close to a good friend of yours and knowing that, oh, well, he could perish in front of your eyes.

“It was probably harder on us than it was on him in that regard.”

And Honnold agreed.

“Typically, watching free soloing is much more stressful than actually doing it,” he said. “Because when you do it, you know how prepared you are and you know how comfortable you are. But when you’re watching it, there’s no sense of control and you’re just hoping for the best. And, I mean, obviously it’s super stressful.”

This is actual life-or-death drama.

“I thought through all the consequences and I imagined what it would be like to fall off in different places and what would happen,” Honnold said. “I think in a lot of ways that’s a healthy relationship with mortality because it’s just an acceptance that we’re all going to die at some point. And I would like to die on my own terms, doing the things that I care about in the way that I care about them.”

The filmmakers also thought about what they’d do if he fell to his death while their cameras were rolling.

“We were trying not to think about that too much, and we would have reconsidered if something bad had happened,” said Bob Eisenhardt, who edited the film. “But I think to honor Alex, we would have tried to make the film.”

Yikes.

“Free Solo” is an amazing documentary. Vasarhelyi, Chin and their team did a magnificent job of capturing both Honnold and his amazing accomplishment.

There were moments when I averted my eyes in terror. But I couldn’t look away. You may not be able to, either.