'Got the shakes in my texting thumb. Going mobile cold turkey is so hard'

I don't fiddle with mine much. I don't have high score on Snake, or download annoying ringtones - I've got a polyphonic version of "A Forest" by the Cure, but that's it. It could be a Swiss Army phone with a saw and a magnifying glass and a plastic toothpick that you wouldn't dream of using even if you had a whole pig between your teeth, but I wouldn't know. I'm not that into phones. I make a lot of calls, and I can text like a nimble-fingered teenage girl. I send gags to a comedian called Andre, TV quotes and insults to my brother Henry, and lovey-dovey stuff to my wife. Oh, and "sorry I'm late"messages to everyone. The mobile's always on - always. Because I might get "that call". The "Anthony Hopkins is very keen to work with you" call, the "you've sold out the Palladium" call, the "come home darling our two-year-old is playing White Stripes tunes on the piano" call.

I don't fiddle with mine much. I don't have high score on Snake, or download annoying ringtones - I've got a polyphonic version of "A Forest" by the Cure, but that's it. It could be a Swiss Army phone with a saw and a magnifying glass and a plastic toothpick that you wouldn't dream of using even if you had a whole pig between your teeth, but I wouldn't know. I'm not that into phones. I make a lot of calls, and I can text like a nimble-fingered teenage girl. I send gags to a comedian called Andre, TV quotes and insults to my brother Henry, and lovey-dovey stuff to my wife. Oh, and "sorry I'm late"messages to everyone. The mobile's always on - always. Because I might get "that call". The "Anthony Hopkins is very keen to work with you" call, the "you've sold out the Palladium" call, the "come home darling our two-year-old is playing White Stripes tunes on the piano" call.

The big switch-off comes at 5pm on Thursday - just before I record The Now Show for Radio 4 - so with rehearsal, technical run and recording, the first four hours are a doddle. Then my first test: the "On my way home, darling - chuck a soup in the microwave and put season three of 24 in the DVD player" call. But not tonight. I'll go home in silence, staring at my lifeless electronic companion as it beckons, tempting me like the smell of a warm pie - "switch me on weakling, switch me on". No. Nineteen hours to go. What's the time? I wouldn't know, my phone's off. I have never felt so alone. Five hours in, this is getting pathetic. Then I wee on the floor.

I should explain. It seems I'm unable to get through a night without a pee. It makes me furious, I won't drink after 10pm (I'm only 31, so this bodes badly). I have it down to a fine art: the trick is to stay as near to sleep as you can while you pee. So - wake up, swear, get the mobile, flip on the address book and in the cool blue glow from the screen hobble to the bathroom without having to switch any lights on. Clever. Not tonight, though - both shins hit the bed frame, then I do my hip on the sink, then the miss-fire. Lights blazing, cross wife, me on my knees mopping a cold stone floor. Give me back my gadget.

The morning feels odd. Porridge, tea and newspaper, all fine, but something is missing, something important - what if "that call" came last night? I feel like I've lost a limb. I'll ring my agent and say I'll be near the landline all day. Her number's in my mobile. All of them are. A comforting list of mates, I'm well liked, I must be, my SIM card's full. My fingers feel odd, twitchy. I think I want a cigarette. I don't smoke. I'll write a script - Dave's normally called by now with notes. Where is he? Does he still like me? Is this loneliness? I feel like writing a country song. What's happening? I survived 22 years without a mobile. I'll text Tomsk - he'll find this funny.

I've just realised the only number I know is my own mobile number. That's tragic. I'll call my mobile and leave a message. Trial separation. Still love you. Want to hold you. Thumb cowboy ready for the quick-draw answer.

This is harder than I thought. I've done it before on holiday but I was disengaged from my life then. I can't concentrate. E-mail! Yes. That's better; the craving's passing, yes. E-mail: methadone for mobile junkies. I'm fine as long as I don't leave the house.

1pm. Not going to make it. Got the shakes in my texting thumb. I'm Gollum. I need that one ring, that special ring, that "precioussssss" ring - "A Forest" by the Cure, that ring.

4:50pm. Just ran my wife to the station. Somehow our goodbye seemed terribly final. Come on five o'clock. How many missed calls will there be? Hundreds. "Where is he? What's happened to Marcus?" Four minutes to go, then I can reconnect with the world. Tell it I'm not dead, I was just going mobile cold turkey.

Three, two, one, switch on: "You have one missed call." One?! It's Mum. Right, so not Anthony Hopkins, or the Palladium, or my genius son? Better send some texts, let everyone know I'm back. Let's never fight again Nokia. I love you.