Another whirl of nightclubs, this time the Roxy and Polo Lounge on Hollywood's Sunset Strip, did little to allay fears that Miss Spears is spiralling rapidly towards a nervous breakdown.
She stormed out of the first after 45 minutes when the DJ at the karaoke-themed night started playing her first hit Hit Me Baby One More Time in her honour.
Fellow clubbers noticed how she continually broke off from her group to go to the toilet cubicle, each time returning looking increasingly unhinged.
Miss Spears had not been seen in public since Saturday afternoon, when she drifted into celebrity haunt the Mondrian Hotel, also on Sunset Boulevard, startling residents with her bizarre behaviour.
At 1pm on that day the popstar arrived alone - this time in a blue wig - and tried unsuccessfully to book a room, since she had neither money nor a credit car, just a piece of paper carrying a partial credit card number.
A source told the Mail: 'She was crying and apparently intoxicated. She kept saying: "Nobody wants me anymore".
A couple of tourists felt sorry for her and took her upstairs to their room. Then they took her to the gift shop, she went back and forth trying on three different bathing suits.
'But bizarrely she then went to the pool and tried to shave her legs. She also went to the hotel restaurant Asia of Cuba for a rest on a chair.
'After that, she tried to get a room again and couldn't get one. She was obviously intoxicated and the hotel didn't want to be responsible for what she would have done in the room.
'She then tried to get a rental car but with no I.D. she was again denied. She was hysterical saying things like, "Nobody wants me" over and again.
'The staff were stunned. she clearly needed medical help but no one knew what to do with her. She was alone and left about 4pm.'
Miss Spears hit headlines at the weekend when she booked into a rehab unit in the Caribbean. The Mail has learnt the trip to rehab was on her mother's insistence.
On Wednesday of last week her mother Lynn - the orchestrator of her career - staged an intervention when she found her daughter incapacitated and sprawled out on the floor in the middle of the day.
According to a source she had been 'partying heavily and was completely out of it'.
Lynn Spears is then understood to have threatened her 25-year-old daughter that she would take her two children from her unless she checked into rehab.
She would spend just 24-hours at the Crossroads rehabilitation facility in Antigua before returning to California.
She subsequently had a furious row with her mother - then in Louisiana - over the telephone.
Hours later, she was to be found shaving off her own hair at a salon, then later having two new tattoos etched into her midriff.
A friend of Miss Spears said that she had been 'thriving on the publicity of her recent behaviour'.
The friend added: 'She feel rejected in her marriage and that he music career is really on the skids. She watched the Grammys recently - not so long ago she would have been up there on stage, now that seems like a distant memory.
'She feels a failure professionally and unloved in her personal life. It's as if she is getting a kick out of doing increasingly erratic things just to see how the public and media react. 'Sadly, she is getting confused by what she sees as adoration, when it's actually her fans reacting in horror