Brad Pitt 'Trying to Move on with His Life' amid Latest Legal Drama with Angelina Jolie: Exclusive Source

Amid Brad Pitt's ongoing legal battle with ex Angelina Jolie and her new claims of past abuse, a source tells PEOPLE he's dedicating his attention to moving forward with work and girlfriend Ines de Ramon.

"The long-drawn drama with Angelina used to really get to him, especially the custody drama and abuse allegations," the source says of Pitt, 60, who shares six children with Jolie, 48: Maddox, 22, Pax, 20, Zahara, 19, Shiloh, 17, and twins Knox and Vivienne, 15.

"It's been very stressful for him to have to defend over and over again," the source continues of Pitt. "But since things don't seem to change, he's trying to move on with his life."

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Pitt and Jolie have faced off over custody (though they've been ruled single, their 2016 divorce is still not finalized) and are currently locked in a legal battle over ownership of their French winery Château Miraval.

Meanwhile, Pitt is focused on his upcoming Formula 1 (F1) racing movie, which he is in the middle of filming. The source says he also "finally feels happy again" with de Ramon, 34, "by his side."

"Although he's always been surrounded by trusted friends, he still had years when he felt very lonely," the source continues. "Sharing his life and living with Ines now makes his very happy. Ines is great. She doesn't come with any baggage and is able to just support him."

Other friends close to the Academy Award winner "just [want] him to be happy," the source says. "He's certainly not perfect. He'll be the first to tell you. [But] he will continue to push back legally."

As part of Pitt and Jolie's ongoing legal battle over Château Miraval, on April 4, the actress's legal team filed a motion seeking to release communications they say would prove Pitt would not let Jolie sell her share of the winery to him unless she agreed to a "more onerous" and "expansive" NDA.

Within the new filing, Jolie's lawyers made the claim, in part, "While Pitt's history of physical abuse of Jolie started well before the family’s September 2016 plane trip from France to Los Angeles, this flight marked the first time he turned his physical abuse on the children as well. Jolie then immediately left him."

The FBI investigated the incident and Pitt was not charged.

A rep for Pitt declined to comment, though a friend of the actor familiar with the litigation over the years maintained to PEOPLE, "This is a pattern of behavior — whenever there is a decision that goes against the other side they consistently choose to introduce misleading, inaccurate and/or irrelevant information as a distraction."

Attorneys for Pitt filed a motion in court on the following day, April 5, demanding that Jolie produce nondisclosure agreements she has made others sign.

The Babylon actor's lawyers seek to prove that the NDA he asked Jolie to sign was no more restrictive than ones she asks others to sign on a regular basis, and alleged that less than six months after Jolie sold her Miraval shares, her attorney proposed an even broader, mutual non-disparagement clause to Pitt in connection to their divorce proceedings.

In their April 4 motion, Jolie’s attorneys suggested the actor feared that sealed documents included in their separate, years-long custody battle could be made public without the NDA.