Jimmy Fallon is getting candid about his mental health struggles when he first tried to make it big in Hollywood.

In a new interview on the Monday, June 2, episode of “The Diary of a CEO” podcast, Fallon, 50, described his frame of mind when he moved from New York to Los Angeles in his early 20s with a dream of pursuing comedy.

"It wasn't the greatest, and I'm a pretty positive guy in general, but I think that was probably my lowest [moment],” the Tonight Show Starring Jimmy Fallon host said. “I remember like, you know, trying to see what therapy was or if I could afford a therapist."

At the time, Fallon noted that he was auditioning for various comedy and acting projects but wasn’t having much luck.

"I think I wrote a letter to my best friend, like, ‘I'm losing it dude,’” the talk show host admitted. “I think it was something to the point, like, ‘I'm losing it and I don't know if I can make it.’”

Fallon also detailed his dogged pursuit of starring on Saturday Night Live — a dream he'd had since childhood.

"I became so obsessed in high school that I couldn't really hang out with anyone while I watched the show 'cause I didn't like it if anyone didn't like the show,” Fallon said of his early obsession with SNL.

In another portion of his conversation with host Steven Bartlett, he added, "My friends would have parties and they go, ‘You gotta come, right?’ I go, ‘I'll be there at one o'clock.’ I can't just tape it. I have to watch it live."

Fallon’s determination to get on SNL continued into his adulthood, he recalled.

"I said, if I do nothing else in life, that's all I wanted to do,” he explained. “And like, even if that, if I got on for one season or one episode, then I could do whatever I could.”

In 2011, the comedian famously told Rolling Stone, “I remember saying to myself, ‘If I don’t make it on Saturday Night Live before I’m 25, I’m going to kill myself.' … It’s crazy. I had no other plan. I didn’t have friends, I didn’t have a girlfriend, I didn’t have anything going on. I had my career, that was it.”

Reflecting on that time of his life, he told Bartlett, "I wrote that in something, in some journal or something. What if I don't get on Saturday Night Live by the age of 25? I'll kill myself.”

Asked whether he meant it, Fallon responded, “Yeah, I did, but again, I knew that I was gonna be on Saturday Night Live."

Fallon did indeed achieve his dream of being a featured player on SNL after auditioning twice. The comedian appeared on SNL from 1998 to 2004 before leaving to pursue a movie career. He returned to television in 2009 as a late-night talk show host on Late Night With Jimmy Fallon — and the rest is history.