R hands me a novel he has been raving about, its protagonist a fortysomething hard-drinking, sex-crazed, successful writer called Kennedy Marr. It is ironic that the book's pages are doused in a liquid that looks and smells like red wine.

"Sorry, something spilt. But read it. It's fantastic."

I finish John Niven's Straight White Male in one sitting because it's funny, sad and brilliant. Kennedy Marr may be a brutish narcissist, an over-the-hill, womanising alcoholic but he is, dare I say it, a character I have sort of fallen in love with. R is my Kennedy, but without the fat paychecks and the house in the Hollywood Hills. Some would say that I have questionable taste in men.

In the real world, away from the vaporous pages of the now well-thumbed book, the only thing I find funny about R's relapses is that they come as regularly as my period: every three weeks. There is a lull, a drought in-between and then suddenly the flood-gate opens and he drinks until he's numb, sometimes for days at a time.

He misses appointments. He fails to show when it's his turn to take the children to school. They wait, coats buttoned and shoes laced. I watch the clock, I text, I call him and my heart sinks when I'm sent to voicemail. I swap my pyjamas for jeans and pile everyone into the car, incandescent with rage, thinking, but not saying, "Your father is a selfish dickhead." He might be both those things, but he is also not well and no doubt pretty miserable drinking on his own.

In the past, in the calm after the school run, I would have texted him "YOU ARE A DICKHEAD." I probably would have waited until he had sobered up, then called again and given him a verbal battering. "Why are you doing this to us? You are a terrible father, and an unreliable, deceitful husband, and I ALWAYS have to pick up the pieces and I have work to do …" yadda yadda yadda, through tears of anger and frustration.

Now, I just sit down and do my work, so I must have moved on. I am learning that confrontation – where words are reactive and spat out like boiling oil – is a waste of energy. I think instead of a passage in Straight White Male. R says it was the part that resonated with him so much that it hurt, and now I've read it I don't know whether to laugh or cry.

Kennedy Marr looks back at his scarred history of relationships with women. He recalls one period when he and his then-wife see a marriage-guidance counsellor. The therapist asks him what he wants. Here's what he thinks, but does not say out loud:

"All Kennedy wanted – all he'd ever wanted – was to do exactly as he pleased all the time in an utterly consequence-free environment. Was this too much to ask?"

This all comes after he has listened to a heartfelt, tearful speech from his wife telling him how much his infidelity, drinking and cruel, callous behavior have hurt her and their daughter.

Reading it for the second time feels like a slap in the face, because R has now admitted how his motives have been governed by a selfish desire to drink, to do exactly as he pleases even when there are consequences.

I can't work out if I am wounded because the truth hurts, or because I know that the hours of talking – either in therapy rooms or in our kitchen, where we've tried to fix our crumbling marriage – have been a waste of time when R still doesn't want to really bid farewell to drink.

The novel doesn't end neatly: there is no great epiphany, and I like this. I get the feeling that a further chapter would see Kennedy Marr downing a few more single malt whiskeys, struggling with his acute self-knowledge yet capitulating in the face of drink and women because he just can't help himself (or just doesn't want to stop). But consequences for a rich alcoholic (as Niven's protagonist is), though still painful, are not quite the same as they are for an alcoholic struggling to pay the rent.

Straight White Male, though certainly not a self-help guide, has given me a clearer idea about how R must feel: the persistent self-torture, the conflicting, nagging monologue that must fizz away inside his head like witches' brew. It seems exhausting, and there is no let up, no prize, no real glamour in the long run when drink is on the mind all of the time.

And yet, as the book so beautifully reveals, the bits in-between the bad, sad times can be funny, fun and glamorous; it's unfortunate that R can't take what's good and leave all the rest.