“Hell on Wheels” killer Mackenzie Shirilla’s late boyfriend eerily texted her about how “there isn’t very much time on earth” as he dumped her a month before his wild car-crash death.

The chilling message, obtained by TMZ, shows Dominic Russo, 20, gently telling his would-be teen murderer that they needed time apart.

“Kenzie u know i love u but i don’t think we should be together at this point there isnt very much time on earth yaknow,” he wrote in the message, which Shirilla read on June 2, 2022 – a month before she intentionally floored her Toyota Camry into a brick wall at 100 mph, killing Russo and friend Davion Flanagan, 19, in Strongsville, Ohio.

“I dont want u to think im abandoning u i wish it could work but i don’t think its going to at this point especially with the threats,” he continued.

“We should just breakup so we can both find happiness somewhere else.”

Shirilla, 21, is serving two concurrent sentences of 15 years to life. She’s now appealing her conviction a second time.

Her twisted saga is the subject of the hit Netflix documentary, “The Crash,” which has catapulted to No. 1 since its debut Friday.

The then-19-year-old killed Russo because their relationship fizzled.

“She had a mission, and she executed it with precision. The decision was death,” Cuyahoga County Common Pleas Court Judge Nancy Margaret Russo said in 2023.

Following the murders, Shirilla posted loving messages to Russo’s online obituary — despite evidence showing that she made zero attempt to brake before the fatal wreck.

“I miss you nug. I still feel like your just going to walk in the door any second. I miss your laugh your perfect smile. I feel your energy around me everyday i just wish it was physical,” a post written on Aug. 24, 2022, under her name said.

“God u are the last person to deserve this you had such a perfect life ahead of you… i wish i told you all this more. Please wait for me​.”

Shirilla was arrested four months after the crash.

She had texted Russo’s mother, Christine, after his death claiming she blacked out at the time and had no memories of what happened.

“I remember turning onto the street, and then my vision fades to black,” Shirilla wrote, according to court documents obtained by People.

“It really kills me not to be able to remember anything. I promise you I would tell you. I’ve been asking my therapist why I don’t remember, and she said it’s because of trauma. I’m gonna try to get myself hypnotized and make myself remember.”

Meanwhile, former inmates have opened up about Shirilla’s life behind bars at Ohio Reformatory for Women — including that her nickname was “Shirilla the Killa.”

Another inmate said Shirilla was like the Regina George of prison — makeup and hair always perfectly done.

“When I was in there with her, you’d look at her and she had her makeup done every day, she was very well put together — almost like preppy,” Mary Katherine Crowder, who served about six months alongside Shirilla, told The Post.