Heather Locklear has been "struggling” with her sobriety after previously battling substance abuse issues. “She has been drinking and told friends over a month ago she wanted to go back to rehab,” a source close to Locklear, 61, and her fiancé, Chris Heisser, exclusively tells Us Weekly. “But she is not in rehab.” While the insider shares that Locklear “hasn’t left her home” recently “except for a few sightings,” the Melrose Place alum made headlines earlier this week when she was photographed looking distraught and walking along the ledge of a building in Malibu, California. Coleman-Rayner “It was very strange behavior to be sure, kind of shocking,” an eyewitness shared with Us about the June 29 incident. “She seemed to be talking to herself, 100 percent. God knows what was going on. At one point she ran across the road making all those funny faces, then she went back and sat by herself. And why she was walking along the wall with flip-flops on? That was a seriously steep drop. If she’d fallen it would have been seriously dangerous.” Locklear has sought treatment several times as she’s struggled with her sobriety and mental health. She completed her most recent stint in rehab in October 2019 and was ordered by a court to continue seeking therapy through an outpatient program. She was also placed on a 5150 psychiatric hold in November 2018 after reports that she assaulted Heisser, 61. Locklear has also faced multiple run-ins with the law. She was arrested twice in 2018 for battering police officers, which almost sent her to jail for 120 days. She instead reached a plea deal that required her to complete a treatment program and remain on probation for three years. While Locklear seemingly celebrated one year of sobriety in April 2020 — “Hugs will come later! 1 year sober today!!!” she wrote via Instagram at the time — the source tells Us that her problems have been ongoing. “Friends say she may never have quit drinking after a judge ordered unsupervised probation in 2019,” the insider says, adding, “She didn’t have any oversight so no one knows if she ever stopped drinking, even back then.” Locklear has also faced personal losses thanks to her substance abuse issues. Two additional sources tell Us that the actress has fallen out with many friends over recent years. Coleman-Rayner “Heather’s loved ones are seriously worried about her and hoping this serves as a wake-up call to get help,” a fourth source adds. “Everyone’s trying to get to the bottom of exactly what’s going on – not just on the day those photos were taken but in general, because it’s very clear something’s not right." Locklear, however, does have family in her corner. That includes 25-year-old daughter Ava, whom the Locklear shares with ex-husband Richie Sambora. An insider told Us exclusively in 2018 that the mother-daughter duo have “always been incredibly close” amid all of Locklear’s personal woes. (Locklear and Sambora, 63, were married from 1994 to 2007.) Ava, for her part, echoed the sentiment one year later, telling Wingman magazine in February 2019: "I would love to follow in my mother’s footsteps.” Locklear and Heisser, meanwhile, were high school sweethearts in the ’70s. They rekindled their romance in 2017, but their relationship has not been without its rough patches. After police responded to Locklear’s home multiple times in 2018 due to fights between the pair, she was arrested for domestic violence. Us later confirmed that the twosome called it quits in 2019. However, they later reunited and announced their engagement in June 2020.