Singer Sinead O'Connor. (Stephen Lovekin/Getty Images)

“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 said in the message. “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.”

Of the tour cancellation, a spokesperson for O’Connor told the BBC, “We have had nothing confirmed yet but are working on the assumption that the statement on her website is correct.”

The “Nothing Compares 2 U” singer announced her engagement to therapist Barry Herridge in early December, wed the next day and announced their separation about two weeks later. They reconciled, but then split again shortly after O’Connor sent troubling Twitter messages asking for help finding a doctor.

Her ninth album, “How About I Be Me (And You Be You?),” was released in February. Allison Stewart writing for The Washington Post called it “breathtakingly good, incredibly awkward.”

O’Connor was scheduled to play shows this spring in Milwaukee, Chicago, Boston, New York City and the District at the newly reopened Howard Theatre. In the message, O’Connor said she hopes to perform at a tribute to Curtis Mayfield in New York this summer.