Sinead O’Connor has cancelled all her planned tour dates for the remainder of 2012 after revealing that she is “very unwell”.

O’Connor, who suffers from bipolar disorder, posted a message via fan website Sinead-Oconnor.com which said that she had suffered a “very serious breakdown” between December 2011 and March of this year and would not be touring for the rest of 2012.

She also said she was advised by her doctors not to tour in support of her new album How About I Be Me (And You Be You)?, but went ahead anyway, a decision she now regrets.

She wrote: “With enormous regret I must announce that I have to cancel all touring for the year as am very unwell due to bipolar disorder. As you all know I had a very serious breakdown between December and March and I had been advised by my doctor not to go on tour but didn’t want to ‘fail’ or let anyone down as the tour was already booked to coincide with album release.”

She continued: “So very stupidly I ignored his advice to my great detriment, attempting to be stronger than I actually am. I apologise sincerely for any difficulties this may cause. While touring will be cancelled I do hope and plan to appear at the Curtis Mayfield tribute in The Lincoln Centre in July.”

O’Connor has endured a difficult year, admitting in January that she took an overdose days before issuing her cry for help on Twitter.

‘How About I Be Me (And You Be You)?’ was released in February and is the ninth studio album of O’Connor’s career.