The question I have a husband and a toddler I adore, and I have the dream job. But although the job is a dream on paper, I am finding myself unhappy in it. Now that I have the perfect career, after finally completing my PhD, having delayed it for maternity, it is somehow disappointing. I am seeing a therapist, but we are early on, and I want the happiness to come faster. The problem as I see it is that what I really want to do is creative writing; I want to write novels. This is very different from all my scientific and maths education, so I am not very qualified for it. I am fearful of failure and of my writing being poor. It seems impossible that I could ever be successful. It also feels impossible to fit it in around my child and life and work. But I also know I will never write a book if I don’t start. When I am writing I feel finally fulfilled in a way I do not at any other point in my life – except maybe when I am reading a really good book. My family is dependent on my salary alone and we want a second baby soon, so it never seems like the right time to spend more time writing or take time off to do something so frivolous. But it’s what I want to do with my life. What should I do?

Philippa’s answer Never label your calling as frivolous. You’ve got to write. Why do we put off the things that we really want to do and mean the most to us? It’s not because we’re too busy or lazy, but it’s often because of our fear of failure. Fear of failure equals procrastination. It can prevent you from even getting started. If you believe your performance says something about who you are as a person, putting off starting can feel like self-protection – it isn’t, it is self-sabotage. For the moment, forget labels like “successful” or “unsuccessful”.

A student asked the late David Young MP, how you get started in the career you want. Young said to him: “Have good ideas.” The student asked: “How do you have good ideas?” Young replied, “Experience.” The student asked “How do you get experience?” Young answered: “Have bad ideas.”

It may seem counterintuitive at first, but Young’s words are gold. Mistakes, failures and setbacks are how we learn what works. It is through our missteps and errors that we gain experience and give ourselves a chance of success. You’ve learned the dream job isn’t the dream job – you needed to experience it to know that.

Disappointments, rejections, failures and setbacks don’t define you, but your courage does. Start writing and fail. Fail again, embrace your mistakes, learn from them. If you are failing, you are doing something and if you are doing something you are giving yourself a chance of fulfilling your wishes, hopes and dreams, and that’s important.

It feels as if you have no time – but you must do this for you, so get up very early in the morning and just write. You will get interrupted, babies will require your attention. Write at work, 20 minutes every lunch time. These times are holding strategies for now. You’re practising. Don’t judge what you write. Don’t think of what you are writing now as something that must be finished. You are in training. Soon (although it will feel like forever before it happens) your children will sleep until 7.30am. You will have 90 minutes every morning. You may even manage one evening a week at a writing workshop. When the babies become children, every year you’ll take a holiday to go on a writing retreat while they’re with their father or granny. Your first drafts will fail, then you edit. You’ll make your failures better. Something big will begin to take shape. You’ll hone it, trim it, reorder it, you’ll sacrifice the bits of it you liked best for the sake of the whole and someone from one of your writing retreats will recommend you to an agent, who’ll recommend you to another and eventually you’ll get your first deal and by your third deal you’ll give up the day job. Well, that’s the idea anyway.

The courage to fail is the same courage you need to succeed, so welcome failure. If you are not failing, you’re not trying, so keep failing. I couldn’t get an agent for my first book. It took me five years to find a publisher. In the end I got one who had initially rejected me. I got no advance. I took every opportunity I had to promote it, even giving talks in bookshops to just five people. In the end I got an agent, I got better deals, I wrote and sold some more books, but I could never have achieved that without failing and failing again.

You are in a hurry, but take your time. The future – your future – will arrive soon enough. Stay in the present, make the most of the children and that job you are not enjoying, but never let go of your dreams, and each day take one small step towards them. When you do that, you are doing something: you are investing in hope.

Recommended reading: How to Fail by Elizabeth Day and The Artist’s Way by Julia Cameron

Every week Philippa Perry addresses a personal problem sent in by a reader. If you would like advice from Philippa, please send your problem to askphilippa@guardian.co.uk. Submissions are subject to our terms and conditions