You’re sitting at your desk at half three on Friday. It’s been a bad day. Through the windows you can see rain bouncing from the playground, and it’s been equally depressing inside. You’ve just had your most difficult class - 80 minutes of ill-tempered conflict at the end of a cold and miserable afternoon. The images are still in your mind.

Insolent Sean, sitting back with his chair on two legs, hands in pockets, grinning round at his admiring audience. Debbie, silently rejecting your attempt to reason with her after the lesson, head to one side looking away into the distance, arms tight folded to keep out the world. And perhaps the most accusatory image of all - Charlie, sitting alone at the back, unhappy, unwanted by the rest of the group, longing for peace and quiet, looking at you with an expression that says: “You’re supposed to help me. Please do something about this.”

As you look round your room, it tells the story. The chairs are scattered - two have been turned over - because the class charged out of the room as soon as you let them go. There’s paper on the floor, some of it, you realise, is the worksheets you gave out for homework.

At this moment, your fellow NQT comes in for a chat, beaming, looking efficient and unruffled, carrying a pile of well-looked-after exercise books ready to be marked. She glances round the room, and you shrink inside.

You drive home in the rain, thinking that maybe you can’t do this job. Perhaps it’s all been a mistake - the years at university, the sacrifices your parents made. You think about your mum, proudly telling people in the butcher’s that you’re a teacher now. If only she knew.

Is it like that for you? And you seriously think it’s only you? You really believe that there are no headteachers who can conjure up the same images, because it was once like that for them? How do you think I can paint such a convincing picture?

Teaching young people has always been a demanding, soul-draining job. To some, blessed with indefinable golden qualities, it might come naturally. Most of us, though, have had to swim upwards against the rapids for a long time, gasping for breath, clinging to rocks, giving thanks for moments of calm.

The most important thing is not to sink, not to think there’s no way forward, not to fall into finding blame and excuses. Long ago, as a new headteacher, I shrank from dealing with a very difficult issue and, after a sleepless night, rang the deputy chief education officer half hoping, I suppose, that he would take the burden upon himself. He didn’t spend long talking to me, but I still reember the two key words - “Tackle it!” he said, quite gently.

That’s what you have to do. You’re in the most worthwhile job in the world. Don’t give up on it. Tackle it.

First, don’t fight any of your battles alone. If it’s discipline, it should be a whole-school issue. The days when teachers had to fight on alone are gone. Never be ashamed to talk about your problems to your line manager or mentor. Ask for support and advice. Ask for the resources you need. Find the teachers who can manage the difficult classes, and talk to them. Would a timetable adjustment help? (NQT with a difficult class, last double period on Friday? Really?) The danger is that your fear of being thought inadequate will stop you from seeking advice. Once you’ve got past that mental barrier, the problem won’t go away, but you’ll know you’re not on your own.

And if it’s not discipline but basic organisation - the feeling that you just can’t keep up with the preparation and the paperwork - then the thing to do is to stop worrying and do something about it. Take a half-term day, or a weekend, go into your classroom and think your way through your week’s timetable. Think about the basic equipment you need for each lesson, make sure there’s enough, and store it in accessible places. Think about the transition from one lesson to another - how do you get one lot of books and equipment out of the way and another lot into action? Can you organise your lesson content to make that easier? Think about your room’s layout. Are you happy with it, or is it time to try another system? It’s not so much the detail of what you do, but that you deal with things rather than just being miserable about them. And again, front up to your colleagues and managers about your problems. They’re there to help.

On top of all that, though, spend a lot of time reflecting on what you do that works. On that miserable day with Sean and Debbie, did you not have a lively and enjoyable lesson earlier with a Year 8 group? You’d forgotten that, because your mind would rather belabour you with misery.

Remember the children who smiled their thanks at you when you explained something, or the ones who came to tell you about the strange-looking dog they saw on the way to school, because they know you have a dog of your own. Remember when a wave of understanding went round a class as you chalked the final figures to an equation on the blackboard. Hold on to these things because, in the long run, there’s going to be a lot more of them.

Finally, let me ask you these questions. Do you like being with children? Can you make them laugh? Do they make you laugh? If so, the job needs people like you. Tackle it.