Multiple sources tell PEOPLE that while the couple initially fell hard for each other, the relationship quickly took a turn

When Amber Heard and Johnny Depp first met on the set of The Rum Diary in 2011, sparks immediately flew between the two – but it didn’t take long for the unlikely couple’s electric connection to turn toxic.

“Johnny and Amber’s relationship was always toxic,” a source tells PEOPLE in this week’s cover story. “They got in so many fights.”

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The “nonstop drama” of their relationship came to a head on May 27 when the actress walked into a Los Angeles courthouse with a black eye and filed for a temporary restraining order against the actor, claiming he had been both “verbally and physically abusive” to her throughout the “entirety” of their relationship.

Along with two alleged attacks detailed in Heard’s court filings, new photos obtained by PEOPLE show the actress with physical injuries allegedly resulting from a violent encounter with the actor. A rep for Depp has not responded to PEOPLE’s requests for comment about the photos, or about Heard’s allegations of abuse.

In court documents responding to Heard’s initial court filing, Depp’s attorney Laura Wasser alleged that Heard “is attempting to secure a premature financial resolution by alleging abuse.”

So where did it go wrong? Multiple sources tell PEOPLE that while the couple initially fell hard for each other, the relationship quickly took a turn.

For much more on Johnny Depp and Amber Heard’s explosive divorce, pick up the latest issue of PEOPLE, on newsstands Friday

In fact, before they ever made it down the aisle, a source says Heard found herself questioning the relationship at their engagement party. “She kind of got cold feet She was just like, ‘What am I doing here?’ When Johnny Depp wants you, you don’t really say no.”

Still, after a whirlwind romance, Depp, 52, and Heard, 30, wed in February 2015.

“Amber is the female version of Johnny,” a friend of Depp’s told PEOPLE at the time. “She’s sort of kooky and outspoken, and while that would intimidate many guys, it is a turn-on for Johnny.”

But Heard’s independent streak and Depp’s insecurities led to jealousy and disastrous dysfunction within the relationship.

“Johnny tends to get moody and difficult and go into himself when things aren’t right in a relationship,” says a source who knows Depp. “When he gets like that, he can act nasty. It doesn’t made for a good marriage.”

And as their divorce battle continues to heat up, those close to both agree that the couple are better off going their separate ways.