How hard could it be to give up alcohol and caffeine for month? This was my question last Thursday as I launched myself into a health drive.

I’d gone for a drink with my friend Sophie, who’d spent three weeks eating vegetables and fruit and drining only water. The results were amazing. She looked like she’d been sleeping 13 hours a night and taking early morning runs on a beach.

Detoxing would be challenge, I thought – but surely not impossible.

Who the hell was I kidding?

I had no idea how hard it would be to turn down a glass of chardonnay on a summer night – or not to have a corona with friends after a long day.

My detox lasted precisely 48 hours.

My first day – Friday – started well. I had fruit for breakfast, and declined cups of coffee. Then I met English friends in the East Village for a healthy sushi dinner. I was feeling hugely virtuous – until my friend poured himself out a bottle of Supporo.

I was hypnotized. It glowed a golden amber. I could hear every bubble fizz. Chilled condensation dripped tantalizingly down the glass.

I tore my eyes away and took a gulp of tepid green tea – but I felt slightly distracted the rest of the evening. It was a relief to get into bed.

Saturday, I worked until 8 p.m. It was the end of my week. To celebrate, a friend who lives in Williamsburg invited me for drinks with her mates at Yabbi’s, their local bar.

I pictured myself sitting in front of glass of mineral water all night, so instead of meeting my friend, I went to the movies with a colleague instead.

During the film, he munched on popcorn and slurped down a great big icy cup of Coke. I clutched a bottle of water.

Afterward, we met up with his friends in a bar. They ordered a round of Manhattans. I drank three orange juices and chewed my straw. Then I went to see another movie.

To cheer myself up, I bought a small bag of popcorn – and diet Coke. I had relapsed. Caffeine never tasted so good.

Sunday, however, I was thrilled to have gotten half way through the weekend alcohol free.

So I braved an afternoon drinks party on a rooftop. My caffeine abstinence now broken, I took comfort in a diet Coke.

I met a couple of friendly actors, who invited me to go out with them after the party.

Naturally, we went to a bar. They ordered a bottle of wine. I was torn. I wanted to hang out and get to know them better, but they were already tipsy. I was out of sync. In the end, I decided to be sociable and allow myself just one small glass. Of course, one led to three.

Horrified by my lack of will power, I tried to restart my detox this week. It lasted two days – until Thursday, when I was invited to a party to launch the new British film, “24-Hour Party People.”

There was an open bar, Moby himself was deejaying. This was one of the coolest parties I’d been to in ages.

“Mineral water,” I told the bartender. “Er, actually, make that a vodka and tonic.”

No! I had to join in the fun. Now, I’m facing the fact that if I want to give up drink I will have to go on a yoga retreat.

Am I an alcoholic? I usually have just one drink per night. I don’t need booze to talk to people. I don’t get drunk – not that often, anyway.

My problem is that that every social activity I take part in New York involves alcohol, and it’s a challenge to constantly turn down drinks. A nice meal practically demands a glass of wine or beer. It seems lame to go out after work and say, “Just an orange juice for me, please.”

And I feel I’m being uptight if I don’t throw back a few at a party. Relaxing is the whole point.

Two days ago I spoke to my friend Sophie. She asked me how the detox was going. I admitted it had been a disaster and complimented her on her incredible will power and strength.

“Oh, didn’t I tell you,” she said. “When I was detoxing, I had to lock myself in a room.”