The drone I can hear, that feels like it's living behind the backs of my eyes, is a cross between the fan in my bedroom and a hangover. Something which I haven't had for a long, long time. But last night I hit the town. I was smiling and happy – and I'm still smiling and happy. I'm really, really in love, passionately in love.

Something has come over me, which I never expected. The austere Georgian architecture, the mounds, the humps, and the vales, the stone, the moss and the green of Edinburgh. I have fallen in love with the city. I keep having to check myself and ask: is it because I left all my work there, or is it because I had a really fantastic two weeks installing my show, or is it because I was treated like a duchess everywhere I went? (Not just in the true cockney sense!) Or is it because everyone is so friendly? My British Airways flight to London City Airport was delayed by nearly three hours, but I was just happy – happy sitting in Edinburgh Airport. I really didn't want to leave. And now I am lying in bed in London, all torn and pulled, because I am supposed to be going on holiday tomorrow, but what I really want to do is go back to Edinburgh, because it's where I felt happy.

I went to a Chinese astrologer once who told me that I had to live so many degrees above the line of the Equator for my soul to feel complete. Everywhere from that point was cold, rainy and Nordic. I never really considered that Scotland is a different country. It's brilliant we can just drive there; we can get on a train and just go there. I was happy with my flight delay, it was like a really good, slow come-down. It made me realise why Hadrian's Wall was there, why it was ever built – and my boyfriend's Scottish!

Today, I feel extraordinarily lucky. My aches and pains are not really from the hangover, even though I did have a few drinks. They are from vast amounts of dancing: spinning, twisting, turning. It's so fantastic and extraordinary when you just allow your body to take over when there is an actual loss of gravity. Not floating, but like a strange connection with a centrifugal force; you can feel yourself leave the earth, but somehow still be connected to it. That's how I feel at the moment and this is happiness.

I'm happy when I forget who I am and I just exist being me. That sounds like a complete contradiction, but it is to do with the balance of the self. I might have to have a little snooze and resume this column later. I am really, really very, very tired.

My retrospective in Edinburgh has been like a massive mirror, and to be honest, there are parts of me that don't reflect that well. Like any middle-aged woman looking at themselves, there are bits I would rather not see. I have read lots of reviews of the show and it's amazing how personal they are. Even the good ones are twisted with backhanded compliments that relate directly to my personality: to the Me. It would be great if one day I died and it turned out that all my work was made by a really thick-jawlined, 6ft 2in Geordie guy and I was just a blink, a fragment of someone's imagination and I hardly even ever existed.

Just the idea of that brings me a massive relief: the idea of not really existing. For years, most of my life, I wished I hadn't been born. Being a twin and for months being in the womb and knowing that I wasn't wanted is something that has played on my mind continuously.

Of course, once I was born I was wanted, but given the choice, most of my life I would rather have not come here uninvited to this world, this planet, to everything I know. But luckily, this is why today I feel very lucky. Art came and got me. Art with its big ideas and its engulfing arms picked me up and swept me away to another world. A world where I exist coherently and purposefully as an artist. I exist in this world, and everything I do makes sense because of that. Without art I am nothing and I am no one. I have just spent two weeks having one of the greatest love affairs of my life, and on that happy note I am going on holiday. See you in September.

Things To Do In Edinburgh:

* Have afternoon tea in the Palm Court of The Balmoral Hotel. The best beef and horseradish sandwiches in the world!

* Lie naked on Arthur's Seat reading Sunbathing Naked and Other Miracle Cures by Guy Kennaway.

* Walk through the Botanical Gardens and listen to the squirrels' mating calls on the way to the Richard Hamilton show at Inverleith House. One of my favourite paintings in the whole world is there; a portrait of Bobby Sands looking like Jesus.

* For dinner, The Kitchin in Leith, five minutes from the city centre. Amazing, fantastic, cool, delicate food.

And if anyone goes to see my show, if you walk behind the Scottish National Gallery of Modern Art there are the most beautiful woods and stream. It's like being in heaven – and heaven is a good place to be on this earth.