Source Says Amber Heard Did What She Did To "Protect Herself" 

Calvin Harris Breaks His Silence on Split from Taylor Swift: \'What Remains Is a Huge Amount of Love and Respect\'

\'I Don\'t Want to Die\': Boyfriend Allegedly Filmed Rape and Murder of 15-Year-Old Girl Found Under Sink

WATCH: Alysia Reiner on Body Positivity: \'I\'m Never Allowed to Ask "Do I Look Fat?"\'

Read the Cover Story: Johnny Depp & Amber Heard: Their Marriage Explodes

Parents of Owen Labrie\'s Victim Sue Prestigious New Hampshire Prep School for Allegedly Turning \'a Blind Eye\'

Tom Brady Shares Fake Rookie Card 21 Years After Being Drafted by Montreal Expos: \'I\'m So Happy I Stuck with Football!\'

Johnny Depp & Amber Heard: Inside Their Toxic Marriage

Father of Murdered Teen Lunges Over Court Table, Attacks Convicted Sex Offender Who Allegedly Killed His Daughter

Ben Higgins "Seriously Considering a Run" for Seat in Colorado House of Representatives

Cam Newton on Helping Kids Pursue Their Dreams on His New TV Show: \'If I Can Do It, Anybody Can\'

En Pointe! Sarah Hyland Shows off Moves in Ballet-Inspired Photoshoot

Gigi Hadid and Zayn Malik Split After Seven Months of Dating

Prince Philip Is Back to Work – 8 Days Before He Turns 95!

Amber Heard \'Did What She Had to Do to Take Care of Herself\' Source Says of Her Divorce Filing

Johnny Depp and Amber Heard had only been married for 15 months when she filed for divorce on Monday, but a source close to the actress says she felt it was a necessary step after months of strife.

"Amber did what she had to do to take care of herself," the Heard source tells PEOPLE.

Tension between the couple started even before they wed, with a source telling PEOPLE Heard expressed hesitation about settling down with the actor 22 years her senior at their engagement party in March 2014, two months after their engagement.

VIDEO: Amber Heard Files for Divorce from Johnny Depp

"Before Amber met Johnny she was just a regular super cool hipster chick living with roommates who dated girls," a source tells PEOPLE. "At their engagement party she kind of got cold feet ... she was just like what is this scene and what am I doing here? She kind of couldn\'t believe it was her life now."

In December 2014, a source told PEOPLE there "is turmoil in the relationship" and wasn\'t sure if and when they would wed.

The couple eventually tied the knot in February of last year. Depp, 52, was not present when she rang in her 30th birthday this past April in Palm Springs.

Heard\'s filing came just three days after the death of Depp\'s beloved mother, Betty Sue Palmer, at 83.

Although the couple never spoke publicly about any discord, Heard acknowledged rumors about the state of their union while speaking with

"I try not to react to the horrible misrepresentation of our lives," she said. "But it is strange and hard."

Please enable JavaScript to view the comments powered by Disqus.

VIDEO: New Jersey Mom Teams up with Tommy Hilfiger on Adaptive Clothing Line for \'Differently Abled Kids

WATCH: Slides Are the Sandal of the Season (and We Found the Comfiest Pair!)

Check out the new PEOPLE Games! Choose from our Puzzler, Style Mahjongg, Solitaire & More!

Queen Latifah, Plus, Kendall Jenner & Gigi Hadid, Eva Longoria & More!

Celeb Babies Make Their Digital Debut

Obsessed or Hot Mess: Check Out These Daring (and Sometimes Disastrous) Star Looks!

Before the Breakup: The Most Romantic Moments from Taylor Swift and Calvin Harris\' Epic Love Story

6 Simple — and Affordable — Ways to Brighten Up Your Home for Summer

Khloé Kardashian\'s Hyper-Organized Medicine Cabinet Will Blow Your Mind: \'I Have a Little Aisle at CVS\'

Elsa Pataky Shares Sweet Photo of Chris Hemsworth Napping with Their Kids: \'Nothing Better than Sleeping in Papa\'s Arms!\'

Why Maksim Chmerkovskiy and Kirstie Alley Aren\'t Speaking

Chris Pratt Flashed Amy Poehler?! Hear His Take – And See Her Reaction

Thank you for signing up! Your request may take up to one week to be processed.