I’m about to leave my first job. I started here 18 months ago as a newly qualified teacher and quickly found out that the “nothing’s as hard as your PGCE” crowd were wrong. I also found that if you can accept that your to-do list is always two feet long and your partner understands that Friday nights are for falling asleep on the couch before Jonathan Ross starts, then it’s still the best job in the world. But as an old hand of five terms, who now stays awake until at least 11pm on a Friday, I decided it was time for a new challenge.

I started browsing through the jobs pages of The TES until “the job” caught my eye. Being a bit of a scaredy-cat when it comes to confrontation (I know, and me a teacher), I waited until I saw the application form before I told anyone at school.

Nothing had prepared me for the awful feeling of betrayal I experienced when I went to see the deputy head that Monday morning; the sense of guilt even outweighed the feeling I’d had when I’d last finished with a boyfriend. Even now, I think it’s the worst thing about teaching. In all other jobs, you get a “dentist’s appointment” and come clean if you get the post. In teaching, you have to face them all, your head of department and the head twice, and there’s no guarantee you’ll get the job.

I needn’t have worried. I walked in and nervously began my “it’s not you, it’s me” speech. But the deputy head was positive, as she always is, and encouraged me to apply - in fact, she was so supportive I began to feel paranoid.

The suspicion grew when several colleagues in my department offered resources and asked me about my lesson plans and - most importantly - what I was wearing. I knew everyone was being supportive, but it felt as if they all really wanted to help me on my way. All that did was make me more unsure about leaving.

I’m well aware of the horror stories about new staffrooms - it’s not that long since I started my current job and had to walk into briefing on my first day praying silently that I hadn’t stolen someone’s seat. Even worse, I’ve just learned my way around the second building of our split-site school and I no longer have to crane my neck at bizarre angles trying to read someone’s name badge before the conversation with them ends. I have learned to love the place. It is not without its faults and I have had some strange and, at times, scary experiences, but they are far outweighed by the fantastic ones.

My colleagues in the English department, three of whom started with me as NQTs, have become good friends, and it is with a heavy heart that I am giving up our after-school “fancy a brew?” chats. My biggest fear is that this chemistry won’t be replicated at my new school, and I’ll be sat in someone else’s chair, unloved, unsupported and alone.

I hope it won’t happen - I’ve met my new colleagues and they’re lovely - but it’s the first time I’ve changed jobs and I’m terrified. Despite all that, I’m looking forward to the new challenge. I’m armed with a map of the school, and secure in the knowledge that all staff wear badges on their jackets. I’ve got a new mug and my own supply of teabags and milk. All I’ve got to hope for is that some kind soul will tell me nicely if I’m sitting in someone else’s chair.

Cheryl Foster teaches in Preston. She starts a new job in September at Hodgson high school in Poulton-le-Fylde in Lancashire