Sinead O'Connor cancels tour following 'serious breakdown' David Wolff - Patrick / Getty Images Contributor Sinead O'Connor performing in Paris on April 15, 2012. Sinead O'Connor is calling a time-out. The Irish songstress, who spent a lot of last year worrying fans with profane, self-immolating Twitter rants, has canceled her 2012 tour on her doctors' advice. And it sounds as if O'Connor has changed her tune with regard to what's plaguing her. MORE: Sinad O'Connor sends Twitter cry for help, says she's psychologically in "serious danger" "With enormous regret I must announce that I have to cancel all touring for the year as am very unwell due to bi polar disorder," she writes on her website. Just days after her days-long marriage to Barry Herridge appeared to end for good, O'Connor checked into a hospital for depression in January after insisting via her website that she was "routinely misdiagnosed" with bipolar disorder when in reality she had post-traumatic stress disorder stemming from her childhood. "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," O'Connor continues. 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. MORE: Wild rock star hairstyles The Grammy winner says that she hopes to be well enough to attend a planned Curtis Mayfield tribute at Manhattan's Lincoln Center in July. Her latest album, "How About I Be Me (and You Be You)," received strong reviews upon its release in February.