Katy Perry has opened up on her mental health struggles.Mentioning dark periods of depression she’s gone through, the singer credited fiancé Orlando for being the ‘perfect’ partner, sticking by her when the going gets tough.Katy, 35, dropped by Howard Stern’s SiriusXFM show this week and discussed a period of depression after feeling a sense of failure following her 2017 album Witness.She said: ‘This record has been interesting to put out in general because it’s during, you know, Looney Tunes times.