Dennis Quaid made a name for himself starring in hugely successful Hollywood blockbusters, including The Right Stuff and The Day After Tomorrow.

But at 64, the actor is almost as well-known for his famously rocky relationship with "America's Sweetheart" Meg Ryan.

In an emotional new interview, Quaid discusses what tore apart their marriage, and why he hit rock bottom after the split.

"The Scarlet Woman"

When Quaid and Ryan met in the late '80s, the actor was at the height of his fame, and Ryan's career was just taking off.

While they could have been a Hollywood power couple, Quaid says Ryan's success actually drove them apart.

"When we met, you know, I was the big deal and then my career [came to a halt]," he told Megyn Kelly.

"And I have to admit it, I actually did feel like I disappeared. I didn’t think I was that small… but I was."

It sounds arrogant, but Quaid insists he's not the same man he was 17 years ago.

"It really was a growth opportunity," he explained. "I learned from that."

The last straw for Quaid and Ryan's marriage was her affair with Russell Crowe, her co-star in Proof of Life.

Ryan says the tabloid scandal made her "the Scarlet Woman" in Hollywood, and insists Quaid wasn't as innocent as he seemed.

By the time Ryan was seeing Crowe, she says the marriage was basically finished, and Quaid had been seeing other women too.

"I spent many, many a night screaming at God to please take this away from me."

While a clean break from Ryan might have helped Quaid, the actor says it only sped up his downward spiral into drug addiction.

Quaid revealed he was "basically doing cocaine pretty much on a daily basis during the ‘80s," and joked that his movie budgets had to account for the habit.

"It starts out fun and then there’s fun with problems, and then there’s just problems," he explained in an interview with Radio Times.

"I spent many, many a night screaming at God to please take this away from me," he admitted to Megyn Kelly.

"'I’ll never do it again because I’ve only got an hour before I have to be at work.'"

The actor says a "white light experience" finally set him on the right path, and he sought counseling for his addiction.

"I kind of realized I was going to be dead in five years if I didn’t change my ways. The next day I was in rehab."

The actor claims he kept off everything - including alcohol - for a decade, using golf and meditation to steady himself.

Ironically, after all the pain and strife he went through, Quaid calls his marriage to Ryan "the most successful relationship of my life."

The actor has since been married and divorced twice. Today he's in a relationship with model Santa Auzina, 31.

Do you remember when Ryan and Quaid were still a couple?

Here are more interesting celebrity stories:

• Kathy Griffin feuds with Ellen DeGeneres, calls her "untalented hack."
• Kim Kardashian mom-shamed over her daughter's new hairstyle.
• Roseanne unveils her new talk show with bizarre video.

[H/T: Daily Mail, Radio Times]