I feel good. I knew that I would now. The reason is that I've returned to my comfort zone. A few weeks ago, my agent asked if I would consider dancing on live, primetime television. Since I'm not a dancer and generally do recorded television, I was, I'm sure you'll understand, hesitant. But the programme was Let's Dance For Comic Relief, and you don't say "no" to Comic Relief – well, not without a very good reason, anyway.

Since its inception in 1985, the charity has made more than 6,900 grants to UK-based projects, and more than 1,800 to projects in Africa and around the world. It is constantly providing vital, life-changing and life-saving support to some of the neediest people on the planet. Refusing to do a live, two-minute dance routine on the basis that you're a bit nervous about it is really not an option.

So began the process of turning me into a dancing queen. You have roughly a week's rehearsal before you're thrust in front of 7 million viewers. My first session began encouragingly. Although I rarely dance any more, I used to take tap lessons, and I've had to learn routines for musicals in the past, so I can move and follow choreography well enough.

I'm also pretty fit – or so I thought. After an intensive two hours with the choreographer on that first day, I started to feel dizzy. It'll be the spins, we agreed. I sat, drank water, walked around in the fresh air. Nothing helped. Eventually they sent me home and I vomited copiously for 24 hours. It wasn't the spins; it was food poisoning. This was good news, however, as my initial diagnosis – that I was possibly the first person in medical history to be allergic to dancing – proved unfounded.

With each passing day, my confidence grew just a little, first because I'd remembered the routine, then because I'd got through the routine, and then because I was actually dancing, not just staggering in time to the music. Once the backing dancers were brought in – as talented and supportive a bunch as you could hope to meet – the pressure went up a notch. This is partly because there is now a group of people doing many of the same moves as you, and doing them properly. But also there are serious health and safety considerations. If a 6ft 2in man is going to leap-frog over your head while you're standing up, you have a certain responsibility to be in the right position for him at the right point in the song. I did not want to put some poor sod in a plaster cast because I had shimmied when I should have slithered.

The night itself is now something of a blur. The other competitors and I formed an unlikely close-knit alliance. We all shared tips for reducing our anxiety, and a great deal of time was spent worrying about how to go to the loo in a leotard. For the men dressed as women – a sine qua non in Let's Dance terms – this was an almost insurmountable hurdle. Make-up and costume transformed me into an unflattering parody of Björk, with a freakish wig and a dress like a wind-sock.

A small child with the face of a fortysomething mother-of-two, I looked not unlike the murderer in Don't Look Now. I was aiming for a somewhat clumpy style – it's what Björk does in the video – but when I watched it back later, it looked as though my relationship with gravity had somehow gone askew. But I got through it.

Now here's the rub: if you win, or even come second, you go through to the final and have to relive the whole terrifying experience. I was pretty confident that a significant proportion of the viewing public would not even know who I was, let alone want to see me thumping around a stage in orange nylon for a second time. I was right. Russell Kane's terrifyingly accurate Beyoncé prevailed, with Katie Price's moustachioed Freddie Mercury a close second.

I'm now free to go about my normal business. The tap shoes can be returned to the friend from whom I had to borrow them, and the false lashes are in the bin. But there have been two major benefits to it all. Firstly, we raised a huge amount of money. And secondly, from now on, I like to think, I shall approach drama and comedy scripts with a new-found swagger: you think that character's going to be tricky? Pah! I've looked ridiculous in front of 7 million viewers. Nothing fazes me.

I've found the perfect man and creative partner...

Right now, the day job consists of writing a radio series with my brother, Jeremy. This is lovely in many ways. For a start, Jeremy is a proper writer. He knows how to structure scripts and develop characters, and everything. Hell, he even does the typing. So all I have to do is chuck ideas about and suggest gags and character foibles. It's like making bread in a machine – the ingredients have to be put in correctly, but then you sort of let it do itself.

I have a vague anxiety that, like the elves in the shoemaker story, he sits up all night slaving away to save me the trouble. But hey, serves him right for teasing me when we were kids. Plus, because he's my brother, I never have to bother dressing smartly. Oh yes, and he cooks too.

We're singing from the same hymn sheet at home

We have a newfound pleasure in our family. Having introduced the children to Edwin Starr's 1970 protest song "War", we have divided up the parts – one says "War", another "hurgh", a third "good God, yo" and the fourth "wwwwwhat is it good for?" with a combined chorus of "Absolutely nothing, say it again" – and we sing it from different parts of the house.

I'm not sure we're benefiting the causes of either music or pacifism, but I recommend it as a way to pass the time and irritate the neighbours.