Britney Spears and her current boyfriend Paul Soliz didn't start fighting Wednesday at the Chateau Marmont hotel on the Sunset Strip ... we're told there's a history of conflict.
Sources familiar tell TMZ ... Britney and Paul were at the Wynn Las Vegas the last week of December, and we're told they got in an intense fight that was so bad ... when it was over their hotel room was trashed. We're told Britney ended up paying the hotel tens of thousands of dollars to cover the damage.
What's more ... during the trip, we're told Paul was driving and damaged her Mercedes.
Our sources say the fighting is constant, in part because, as one source put it, "Britney is out of control, and it's so bad I'm afraid of the worst." Two sources familiar tell us her mental state is on the level of pre-conservatorship and getting worse.
We're told Britney has no one who can direct her to receive medical and psychological help, and at this point, her doctors are stymied.
According to our sources, the person who's now running the show at her home -- her former maintenance worker and current BF, Paul Soliz. We're told he orders security around and is Britney's go-to.
TMZ broke the story ... Britney and Paul were at the Chateau Marmont Wednesday where they were drinking and ended up in an explosive fight that concerned many hotel guests, who believed she was having a mental breakdown.
Aside from the fight with Paul, we're told she was "harassing and threatening" staff and guests. Our sources say she was screaming in the hallway half-naked before an ambulance showed up, but she eventually left on her own.