Billy Porter says a poorly treated urinary infection nearly killed him.

On Wednesday, the 56-year-old Broadway icon appeared on “Today” to promote his new children’s book, “Songbird in the Light,” and discussed a recent health scare that’s given the actor a new outlook on life.

“I am on the road to complete recovery,” he said, tearing up. “It is a gift to be alive. It’s still emotional to talk about it.”

Last year, Porter crossed the pond and made his West End debut starring as the Emcee in the musical “Cabaret,” which ran Jan. 28 through May 24 at London’s Playhouse Theatre. The Tony-winning actor said he was having a ball and living his purpose, but then he got a urinary infection.

“The medicine in the U.K. is trash,” he told “Outlaws” podcast host TS Madison earlier this month. “Four rounds of antibiotics and 10 to 12 weeks later, it’s a kidney infection with kidney stones.”

Porter eventually thought the infection had cleared up and returned to New York, where last fall he was gearing up for a Broadway revival of the musical starring as the production’s first Black Emcee, but his history-making run was cut short.

“I go into rehearsals for ‘Cabaret’ on Broadway … and everything seems fine, and a month in, the kidney stone pain comes back,” he told Madison.

On a Tuesday in September, Porter checked himself into the hospital due to debilitating pain, and then the “Pose” star subsequently fell into a coma and woke up days later on a Saturday evening.

“They went in to do a routine check. They saw that the kidney stone was trapped in my urethra, and they went in to put a stent in, redirect the urine, blast me with real antibiotics — not U.K. antibiotics — and blow up the kidney stones. When they got in there, there was so much pus and bile and infection behind the stone, it bubbled up and I went uroseptic in minutes.”

“I was dead for three days,” Porter said.

Porter said he was placed on an ECMO (extracorporeal membrane oxygenation) machine, which, according to Mayo Clinic, pumps blood outside of the body to a heart-lung machine, removes carbon dioxide from the blood and sends oxygen-rich blood back to the body. It’s essentially a life-support system.

While Porter was in a coma, he said, one of his legs went into compartment syndrome, which happens when there’s too much pressure around your muscles, causing reduced blood and oxygen flow and possibly leading to necrosis. “They had to cut me open on either side of my leg while I was in a coma, from my knee to my hip, and leave it open for two days so they could save my leg,” he told Madison, visibly choked up over the ordeal.

Porter told “Today” that the experience was mind-altering yet also inspiring. “My work here on this earth is not done, and that gives me hope.”

His new children’s book, “Songbird in the Light,” which follows a young boy who grapples with bullying while learning to embrace his talent and love himself, hit bookshop shelves this week.

If you were ever a giddy kid who spent summers hanging out with friends, making crazy pop videos, goofy short films, and composing off-key songs you were convinced were going to make you stars, then Summer 2000: The X-Cetra Story is the exact film you should watch, enjoy — and then have a bit of a cry after, mourning the happy, creative child you once were before you turned into whatever you are now.

Precisely distilling that tangy mix of nostalgia, joy and regret, this delightful SXSW-premiering documentary tells the story of X-Cetra, an all-girl garage band that three 11-year-olds and one 9-year-old in Santa Rosa, California, formed in the year 2000. With help from two of the girls’ mother, herself a home-studio musician-producer, they made one album on a set of CD-Rs that became, two decades later, a viral phenomenon among fans of outsider art, generating tributes from prominent music publications including Rolling Stone.

As it turns out, one of the members of X-Cetra is Los Angeles-based actor Ayden Mayeri (I Love That for You). Drawing from her experience as a filmmaker, Mayeri documents X-Cetra’s reformation both as an onscreen participant and this film’s director and co-writer. (Fellow performer Barry Rothbart takes credits here as the film’s co-writer, producer and cinematographer.)

Like the scrappy, unvarnished but sort of brilliant music the band made back when they were kids, the film itself is a little all over the place and arguably would benefit from some editorial tightening up, but it’s clearly made with love. Best of all, that generosity of feeling and affection applies not just to what the X-Cetra members feel for each other, both back in the day and in the present even after having drifted apart over the years, but what they feel for their young selves. In the end, it becomes a celebration of girlhood genius and the fearlessness of youth, festooned with glitter and fiercely crop-topped.

Also, given that we’re in a cultural moment when we’re being bombarded, mostly for righteous reasons, with grainy, slightly unfocused images of nubile young women who were abused by the likes of Jeffrey Epstein and others, it’s refreshing to see Mayeri and her friends’ snapshots and know that, for the most part, these were relatively happy kids.

That said, the film does touch on some of the darker feelings lurking under the surface — especially for sisters Janet and Mary Washburn, who left their father back east after he and their mom, Robin O’Brien, got divorced and Robin took the kids west to live in the Bay Area. The film also carefully explores how younger sister Mary felt abandoned by her friends when they all went up to high school and stopped bringing her along to parties where the older three — Mayeri, her best friend Jessica Hall, and big sister Janet (now Janet Kariuki) — started to explore their teenage sexuality, an environment inappropriate for still prepubescent Mary. Later, the film softly probes sore spots like how the older threesome also drifted apart over the years, and how Ayden and Jessica’s bond was especially tested by Jessica’s relationship with a psychologically abusive boyfriend.

Those dark passages add shade that balances the very sunshine-y material that makes up the vast majority of the film. Frenetically cut, perhaps intentionally in the fragmentary style of an early aughts pop video, the work flicks back and forth constantly between footage of the four women today and their younger selves, who made full use of early digital technology of the time to record their antics.

With all this fizzy activity, it’s not clear when Mayeri and Rothbart decided to start making this film — in other words whether it was before or after X-Cetra’s first and only album, then called Stardust, was uploaded to a specialist music site from whence its viral career was launched. Ultimately, it doesn’t really matter, but the sequence where they find out first that the The Guardian in the U.K. and then Rolling Stone are interested in interviews with them feels a little disingenuously presented so as to buttress the fairy-tale success story the film is selling.

But just as a mini highlight reel of Mayeri’s best bits as an actor illustrates, she has great natural comic timing and that serves her well here as a director. She also coaxes her friends well in the interviews — these women who are clearly not as at ease in front of a camera as she is — so that they feel secure enough to open up. Gradually, they fill out as “characters” in their own right in the comedy-drama of the doc, all of them enduringly regular but also individuals with complex inner lives. That fine line between banality and brilliance is one the film navigates throughout with grace.