Last autumn, as the leaves turned, I felt a cloak drape over my shoulders, a leaden, winter cloak weighing me down. And rather than being able to shrug it off, it came with me everywhere. I was able to feel the threads lighten when I was laughing, or crying, but was unable to cast it off completely.

It was almost a year since my father's death aged 60 after a long illness. In that year I'd gone from numb shock – nothing had prepared me for this expected departure – to deep, dizzying sadness, where I understood what other people who had experienced grief meant when they wrote of the sky turning from blue to black.

Slowly, I was able to enjoy the memories of the time we had spent together while my dad was sick: the hundreds of games of chess we'd played (I always lost, even when he was very ill indeed with cancer, his slim frame so undernourished that his bones jutted out, he would trounce me into checkmate) and his obsession and delight with food as eating became increasingly painful.

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His requests for ice-cream combinations that may be for sale in the best gelaterias in Italy but aren't readily available in Nottingham; his rhapsodies over toffee pavlova and his theory that McDonald's had very deliberately set out to corner the market of people who want to eat but have lost their teeth. The trip to the country fair at Abergavenny, his childhood home in Wales, where there was still an annual garden-on-a-plate competition, and the most beautiful memory of his pride and delight at meeting my nephew, then a tiny baby, who shared his name, William.

I didn't know that grief commonly returns, that this was my body marking the anniversary of the death of my dad the year before. It was with this sadness that I arrived one day in October at a yoga studio, neither strong nor flexible, surrounded by people whose bodies seemed as lithe as dancers' (I've found out since that some of them are dancers).

I'd love to be able to say it was some kind of personal peace-finding mission that brought me to the yoga mat, but I wasn't nearly conscious enough to realise that. All I knew was that my mind – always full of idle chatter – was whirring at great speed, screaming so loudly I'm almost surprised other people couldn't hear it. Far from yoga magically stilling my mind, it continued apace through my practice. But at least when I was on the yoga mat I was aware of the constant humming: much of the rest of the time I was so sucked up in my thoughts I couldn't even see them repeating themselves in my head time and time again, hundreds of thousands of times. I would hide in the corner, wishing myself invisible – I didn't want anyone to notice me and my not-touching-toe ways. I had no idea how to make the postures, known by their Sanskrit term, asanas, look graceful: it was the most I could do to complete a class. I would take the child's pose, with my chest and forehead resting on the ground and my heels together, often, yet by the end of each practice my clothes would be drenched with sweat.

But something kept drawing me to my mat. Somehow, doing something where I didn't expect myself to achieve or be excellent gave me a sense of freedom. I had no expectations; this was just for me. And slowly I started to see small changes in my body: I felt lighter, more free, and it wasn't simply just a case of surviving class, I could actually feel my body, check whether I was stacking my joints, have some awareness of whether I was locking in my core.

I started going to workshops run by the studio, Hot Power Yoga in Clapham, south west London. First a beginners' workshop, where I was so full of questions about how yoga has effects on the emotional side that I signed up for a teaching foundation workshop. Still, I wanted more, and at the beginning of this year I signed up for HPY's teacher training course. I had no plan to teach yoga. I was adamant that it was simply to deepen my own practice, and remember telling the studio founder Dylan Ayaloo, and his co-facilitator Craig Norris that I was no yogi. "There are things I'm very good at. Yoga is not one of them," I told them.

This is not the story of a graceful transition from duckling to swan. The training was intense, and at times I found myself frustrated with my body. In all yoga postures there is a sense of tadasana, meaning shoulders being low and back. I spent a lot of time hunting for tadasana in my downwards-facing dog, a fundamental posture where the body forms an upside down V shape, but it kept eluding me. My posture, from many years hunched over a computer, leaned more towards "desk-asana" and I remember feeling emotional when I looked in the mirror and saw that my shoulders were so close to my ears when I was standing upright, the chances of them suddenly lowering when I was half-inverted were slim. We learnt about anatomy and the asanas; the effects they have on strengthening and flexibility. But this was the very surface of the course. More importantly, I learnt about me: to watch the whirring that goes around in my head, gain some distance from it and see the patterns that play out and affect my life, to recognise that this is not who I am.

I saw that I give myself a really hard time by spending so much time trying not to make mistakes. And I recognised that the biggest mistakes I have made haven't turned out as badly as I imagined, they've been the things I've learnt the most from – something I can't regret. I'm a real striver, and experienced deeper freedom learning that I'll never be perfect: sometimes it's good simply to congratulate myself on where I'm going right.

Dylan, founder of Hot Power Yoga and lead facilitator of the training, says: "The physical practice of yoga – although the most well known – is simply a tool to facilitate transformational change. Focusing on the body provides a break from the mind. In showing students how to gain some separation from their thoughts comes a greater level of self-awareness and clarity on the patterns that influence and run their lives. It's an ongoing journey but one which brings a greater sense of freedom and empowerment." It is a journey I welcome, though the very first step was bumpy.

My fellow teacher trainees were intimidating. Three were professional dancers; some could casually flick their legs behind their heads, others would balance on their forearms or throw themselves up into handstands. I was in awe, felt very shy – and out of my depth. Over the two months of training, they became good friends.

I'd still be delusional if I thought I would be a contender for yoga if it is introduced to the Olympics, but I can now touch my toes; balance on my arms in crow pose; my core is strong and my shoulders are dropping away from my ears and slowly freeing up as I no longer feel I should carry the weight of the world on them. One day I will have a pleasing upside down V in my downwards-facing dog – sometimes I already catch glimpses of it.

And I've surprised myself: I'd expected to use the teacher training to learn more about yoga, to deepen my practice. I hadn't expected that six months after wishing myself invisible in class, I'd be at the front, teaching other students at regular classes.

While I'm at the very beginning of my journey, I have learnt that yoga helps me cope with grief. It gives me a sense of grounding, the sandbags to shore up the watery wash of my emotions. A distance that means I can sometimes get a sense of a bird's eye view, rather than a bug's eye view, and a way to feel my body. The chattering of my mind certainly hasn't stopped, and I don't believe grief – or any strong feelings – just disappear.But with a little distance from the emotions that flooded so forcefully through me, I feel that I've got the tools to start to help others who may come to the yoga mat for more than just a bikini body.

Genevieve Roberts teaches yoga classes in London: see her blog: FindingSunshine.me