As the clocks strike midnight on New Year’s Eve, I will finish a 12-month stretch of self-imposed sobriety. A year ago I had got to a point where I was drinking and smoking too much and – until the moment when I decided to quit – I was largely in denial about the impact it was having on my health. The scale of my drinking was normal for the social circles I was in. Whether the people I was with came together through work, football or friendship, drinking was commonplace.

But by the end of 2016, I felt uncomfortably overweight and my mental health was getting worse. I regularly experienced what I would describe as depression and felt weighed down with angst. On hindsight, these feelings were particularly pronounced after drinking, but they were becoming routine.

I was often telling myself I wasn’t good enough or that I was failing in my professional life. These thoughts were irrational, but as a driven person, keen to push on in my career in public relations, they were all the more intense.

My dad made a comment I found irritating at the time: that I looked a little overweight and that alcohol might be the reason

A couple of incidents over the Christmas holidays helped make up my mind. My dad made a comment I found irritating at the time: that I looked a little overweight and that alcohol might be the reason. Then my brother, having been booze-free for two months for his own reasons, tried to recruit me to teetotalism. He said quitting alcohol would make me perform better at work. Although this appealed, I wasn’t convinced I wanted to be a guinea pig for his experiment.

After a late breakfast on New Year’s Day, I announced to my girlfriend and housemates that I was quitting alcohol and cigarettes for a year. Understandably, their first reaction was to laugh.

To begin with, my method of dealing with the social awkwardness of not drinking was to self-advertise – I told anyone who would listen that I was going booze-free. Like any good boxing promoter I talked up the challenge, creating the pressure I hoped would keep me motivated.

The first six months were challenging. I was lonely at times. I felt annoyed when I wasn’t invited out, and extremely frustrated by how much people’s lives seemed to revolve around drink.

But I soon began to notice the benefits. I had more money, which meant I was less stressed. I slept better, which meant I was sharper at work. I spent time with my girlfriend and visited galleries and restaurants.

Around this time I spoke to a GP, telling him with pride about the impact sobriety was having on my mental health. Two things he said made perfect sense. First, that the impact of alcohol and cigarettes on our health is broadly linear – the more we consume, the more our health worsens. Second, the most likely reason for the improvement in my mental health was that I had made a conscious decision about how to live my life.

So many people my age – often in busy, stress-inducing jobs – gather over drinks to give them a release, and I was no different. But that became a banal existence – every social occasion morphed into one because each was defined by alcohol. For me, going without alcohol represented an exciting opportunity to live differently – to assert my independence. By actively taking a different path, I began thinking creatively about how to spend my time, and this meant life became more interesting. And because I was making positive decisions about how I wanted to live, my sense of self-worth and wellbeing improved.

Twelve months on, I feel better than I ever have done. I don’t wake up gripped with anxiety or suffer regular crises in confidence. While I won’t smoke again, I will drink, but only occasionally and for fundamentally different reasons from before. I feel apprehensive about my first drink, but that’s a good sign I think.

• Ned Lamb is a public relations director