During an appearance on the "Anna Faris is Unqualified" podcast, the "Lord of the Rings" star got candid about his past loves and confessed that his biggest heartbreak was from his breakup with his "Lost" costar, Evangeline Lilly.
"I've only really got my heart broken once in my life," Monaghan began. "I was dating an actress on Lost called Evangeline Lilly, who, you know, has gone on to have a name all of her own. I don't really know how she would explain the narrative, but from my point of view, it was probably the first time in my life that I was all in."
Dominic and Evangeline began dating in 2004 and later split in 2007. The 45-year-old actor revealed that the couple had been discussing marriage and starting a family.
Although the couple were in serious talks about taking their relationship to the next level, Monaghan revealed that his excessive drinking and partying led to their inevitable breakup.
"Even though I would get my work done and at that point I was a very committed actor to Lost, I would only consider it a weekend if I was drunk out of my mind on a Friday and Saturday night. I thought that was normal," he said.
"And I think if you are drinking often, probably your behavior and your choices and your mood is up for debate. And I think Evie was pretty straight down the middle. You know, I think she was pretty solid," Monaghan continued.
"Of course, she enjoyed a glass of wine, but I rarely saw her get inebriated. And of course, she enjoyed a party and all that kind of stuff. But I was always the guy that wanted more. I always wanted to drink more, take more, stay up the latest, go on benders," he said. "And I just thought that she was okay with that. And I think probably she was consistently exploring the idea of like, 'Well, this is okay for a time, but, you know, he's not gonna be a great dad or a great husband because he's got all this work to do,' which I certainly did."
"So outside of me knowing it, I think she was kind of looking around to see what else was an option. And unfortunately, there was a little bit of a crossover, which was pretty upsetting for me," he went on to recall his memory of events.
"And it just kind of exploded in my face, you know. I mean, it exploded in my face in like an awful way because, you know, not only do you go through a public breakup, because at the time, that TV show Lost was kind of a big deal around the world. So it was kind of known that we were together and then known that we were not together."
Monaghan said it wasn’t until after a particularly rough that he realized he needed to make a change.
"So I think the moment where I was like, 'You have to sort your shit out,' was ...This is kind of weird to admit, but it -- it just happened. This is just the truth. I woke up one time on my kitchen floor," He said. "This is years ago. This is like in the middle of the breakup, probably, I don't know, two or three months into this breakup. But I woke up on my kitchen floor. Didn't know what time it was. All my house was like black. It was clearly like, you know, the sun had gone down.
"And I was surrounded by pills, like a blue one, a red one, some white ones, a green one, a pink one, half of one. And just general detritus of clearly just a mess. And I was messed up. You know, kind of medicated, and didn't know what medication I'd been on. And I kind of sat up and pushed myself next to this kitchen counter and tried to kind of sober up a little bit," Monaghan said.
"And I looked at this mess in front of me, and I thought, 'That could've been it.' You know what I mean? 'You could've accidentally taken the wrong cocktail of stuff, mixed with alcohol, mixed with where your heads at, and it could've been it. You're not gonna die over this. Like of course it's sad, and you're devastated about it, but you're not gonna die.' So at that point, it was like a big turning point."