Luann De Lesseps Checks Back Into Rehab — All The Details On Her Shocking Booze Relapse

Luann de Lesseps is checking back into rehab just months after her first stint in treatment, RadarOnline.com can confirm — and she's skipping the Real Housewives of New York reunion to get help!

"This weekend, Luann was surrounded by her girlfriends and decided — with their support — that in light of recent circumstances, it is the healthiest choice for her not to attend Tuesday's reunion taping so that she can continue in her healing process," her RHONY costar Bethenny Frankel told PEOPLE. "Luann is now surrounded by a core group of people who truly have her best interests at heart and who are working to make sure she gets the help she needs."

RadarOnline.com can exclusively report that the 53-year-old reality star has been back on the booze for a least a few months, since the latest season wrapped filming.

"She was sober during filming, but is back to drinking," a source recently told RadarOnline.com, pointing out "she never promised to be sober forever."

Despite her December arrest for allegedly beating a police officer while under the influence, the hard-partying star "doesn't think she has a real problem," the source added. "She knew she should be sober on camera, but now she thinks she can drink in a low-key way."

But apparently she was wrong.

A friend said she was acting careless in recent weeks with her drinking. An onlooker told RadarOnline.com she seemed to be under the influence at San Francisco Pride weekend in June.

Another source recently told RadarOnline.com that her daughter Victoria, 23, and son Noel, 21, had "cut her off" in recent weeks, as the adult children and their father sue the star for allegedly refusing to set up their trust fund.

She also has been isolated from her RHONY family and other friends, the souce claimed.

As RadarOnline.com previously reported, de Lesseps was arrested on December 24 in Palm Beach, Florida for allegedly resisting arrest, disorderly intoxication and beating a police officer after she refused to leave a hotel room.

In police video obtained by RadarOnline.com, she screamed "I will kill you" to a cop as he attempted to arrest her.

She accepted a plea deal by pleading guilty to misdemeanor charges, and will return to court later this month.

"I couldn't continue living the way that I was living," she told PEOPLE in April. "The only place where I felt like I was going to be okay was rehab."

Before she returned to booze, de Lesseps was reportedly smoking weed. In April, Page Six claimed she was seen smoking marijuana outside a New York hotel.