Britney on the brink: New fears as singer publicly breaks down

The former pop star had spent much of the day holed up in her home following a judge's decision to allow her only supervised visits of Sean Preston,2, and Jayden James, 1.

As she slipped out for a Starbucks run, it was clear the 25-year-old had been crying and appeared to break down in her car as she clutched her Yorkshire Terrier.

Britney's aunt Chanda McGovern recently spoke of her family's fears for the troubled star.

She told The Sun: "We are worried about suicidal tendencies in her."

"Everything is spiralling [out of control]. And whether it be intentional or accidental, there may be a drugs overdose."

"It's heartbreaking. Everybody is human she just needs to come back down to earth."

Her meltdown comes as more details emerge from the latest hearing in her custody battle.

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Commissioner Scott Gordon ruled Britney - who did not attended court on Wednesday - is allowed to see her children but only in the presence of a professional "monitor."

Sources say she will not be able to be alone with her children at any point during her visits.

The supervisor has the power to end Britney's visits "immediately if any conduct or action by the Petitioner (Spears) endangers the minor children."

The judge also re-ordered Spears to undergo drug testing, and said that he could regard any missed test, or a refusal to take a test as a failed one.

Britney reportedly missed two random drug tests earlier this month after sleeping in, according to reports out of the US.

She was also told she had to complete at least three individual counselling sessions by the next court hearing on October 26.

Sources say Britney is planning to check into rehab once again in a last ditch attempt to regain custody of the children.

The source said: "She said she is willing to do whatever it takes to get her boys back, including giving rehab a serious go this time."

Meanwhile, sing Sinead O'Connor has invited the Gimme More singer to stay at her house to escape the media attention surrounding her private life.

The Irish star, who suffers from manic depression, said she felt sorry for the pop princess - and did not think people should criticise her as a mother.

"We all mess up, don't we, as moms, we never always get it right," the Nothing Compares 2 U singer told Oprah Winfrey on her US talk show.

"To attack someone as a mother is dangerous. Some people may really end up regretting the way they're treating her."

Mother-of-four O'Connor, 40, appeared on the show to talk about her struggle with bi-polar disorder.

Asked what she thought about Britney, she replied: "I feel sorry for her — she's only a young girl. She's had two babies in the space of two years, it doesn't seem like she has had a terrible amount of suppor t from the people around her."

When Winfrey asked what she would say to Britney should they meet, O'Connor said: "I'd invite her to come and live in Ireland — really — to escape. It's impossible, I feel so sorry for celebrities in this country. It's impossible to live a normal life."