Roy Keane has described himself as living with a “self-destruct button” as he looks back over his tempestuous career and tries to explain his old drinking habits and how difficult he found it to adjust to life after playing football. Keane, opening up in his new autobiography, admits he “used to go missing for a few days” before giving up alcohol and paints the picture of someone who has struggled to cope at times. “My mid-life crisis has been going on for years,” he says.

Keane uses his book, The Second Half, to be heavily critical in passages about Sir Alex Ferguson and some of his other former colleagues at Manchester United but the person he is hardest on is himself, questioning whether his issues stem from low self-esteem and admitting that his former team-mates used to be wary of going out with him because he was “a time-bomb”.

“Anger is a useful trait. But when I’m backed into a corner, when I get into situations, professional or personal, I know deep down that when I lose my rag, and I might be in the right – it doesn’t matter – I know I’m going to be the loser,” he says.

“I will lose out. Saipan and the World Cup – ultimately I lost. Or when I left United, when I could have stayed a bit longer if it had been handled differently. I was the one who lost; I know that. That’s the madness of me. When I’m going off on one, even when I might be right, there’s a voice in my head going: ‘You’ll pay for this.’

“That’s the self-destruct button. I don’t know if it’s low self-esteem. Things might be going really well, and I don’t trust it: ‘It’s not going to last,’ or ‘Why am I getting this? Why are things going so well? I’ll fuck things up a little bit, then feel better myself.’ I might be buying a car: ‘Who do you think you are buying a new car?’ And I’ll fuck it up. I’ll drag things down around me.

Facebook Twitter Pinterest Roy Keane has been critical of Sir Alex Ferguson and some of his other former colleagues at Manchester United in his book. Photograph: BPI/BPI/REX

“The self-destruct button is definitely there. And I suffer for it. With my drinking, I used to go missing for a few days. I think it was my way of switching off, never mind the consequences. It was my time. It was self-destructive, I can see that, but I’m still drawn to it. Not the drink – but the madness, the irresponsibility. I can be sitting at home, the most contented man on the planet. An hour later I go: ‘Jesus – it’s hard work, this.’

Maybe ‘self-destruct’ is too strong a phrase. Maybe I play games with myself. I have great stability in my life. But then, that worries me. I like home comforts, but then I want to be this hell-raiser – but I want my porridge in the morning. I want my wife and kids around me. I’ve dipped into this madness, and I don’t like it that much. Maybe I’m like every man on the planet – I don’t know; I want a bit more than what’s on offer.

“My midlife crisis has been going for years. Someone once said to me – an ex-player and it’s going back to my drinking days – that going out with me was like going out with a time-bomb.”

Keane says there were days at the end of his playing career when “self-pity kicked in” and opens up on his struggles sometimes to contain his rage. “When I have been angry that’s been me defending myself. There is a difference between anger and rage. With anger – when I’ve been angry – somebody with me, or even myself, can pull it back. But with rage, I’ve gone beyond all that; it’s beyond anger. It’s rare – even more so now that I’m not playing football. There’s no control with rage. It’s not good – especially the aftermath. You’re coming down and it’s a long way to go. The comedown can be shocking in terms of feeling down or embarrassed by my behaviour, even if I feel that I wasn’t in the wrong.”

Keane also accepts that his reputation means strangers are naturally wary in his company but argues that he is not the person many think. “I don’t get as angry as people might think. But it might help me. As soon as I walk into a room, I know people are apprehensive; I know they are. They are expecting some kind of skinhead thug. So I’ve a good way of disappointing them. I think I treat people pretty well. I’ve got friends I’ve known for 30 years. If I was some impatient thug, I think they’d keep their distance from me.”