Last year, in my 11th year of marriage, I had an empty fling over the internet with an ex-boyfriend. We never met, but it excited me. It made me feel powerful and able – a far cry from the way I was feeling after seven years of being a stay-at-home mum.

My behaviour had a positive effect on my marriage – more sex, fewer arguments. I felt like my old self before children, before I donned the invisible and diminishing role of housewife. I was distracted enough to forget my discontent. When the fling finished, I felt bereft and bored. I searched online on an extra-marital affairs site and have been having an affair for a year.

In the early days of the affair I still enjoyed my husband, but find now that I increasingly dislike him. I have been spoiled by the adoration, attention, care, support from this new man.

Yet, I think that if I try harder with my husband, I can make our marriage work, at least for the time being. I cannot see myself living with my husband until our dying days. I will leave when the children are old enough to understand. I want to live alone. I yearn for a fantasy world: a little house of my own, with a one-week-on/one-week-off arrangement with the children (now eight and six), providing for myself and children, succeeding on my own.

I’m not going to give up my affair – I’m not sure it would help if I did. I fear it would leave me resentful, bored, irritated and prone to arguments. But how can I give my marriage the attention it needs while I’m having an affair? I’ve decided to be fairer. Stop this voice in my head that says I sodding hate my husband every time he annoys me. Give it two more years for our respective businesses to stabilise. So. It’s not good enough to stay, but not bad enough to go. I need an omnipresent entity to tell me which direction to take, and, unfortunately, my husband to tell me whether I can afford it!

Anon, via email

I want you to read your letter back to yourself, as if it were written by your husband instead of by you. How would you feel?

I understand what absorbing yourself in motherhood can do, but it doesn’t have to be that obliterating. I am surrounded by people who are married but indulge in some sort of fantasy life. I see nothing wrong with fantasy. I understand that you can neglect yourself after you are married or have children. I don’t mean neglect yourself in the way women’s magazines might mean it: I’m not going to suggest you need a new hairstyle or a pair of shoes. I mean in doing things that make you you. Whatever that is. But you are indulging in fantasy in the wrong places.

If you want out of your marriage, then leave (try a marriage counsellor first, via relate.org.uk). But be clear about what you’re doing, and why. This is where the fantasy has to stop.

Marriages rarely fix themselves. If your husband annoys you so much that you use the word hate in relation to him then it really is time to do something about this, for all of you. You may be annoying the hell out of him, too. He may be the nicest man in the world or he may be a brute, but ultimately you are in charge of your own life and happiness. You need to be an active participant and stop blaming others for your life, your unhappiness.

I want to be kind to you, but part of me is irritated by just how self absorbed yet un-self aware, you are. This would be a dangerous enough game (I say this not as a moral judgment but in the way you are unable to contain what you’re doing) to play if you didn’t also have children. But you do have children and you really need to think of them, actively, not just as a result of your bad marriage, something you can share a week on and a week off. At the moment you feel wronged and therefore justified in your actions, but if you were found out the roles would change fast.

I know women who wait to leave bad marriages until the children are “old enough” – they become shadows of themselves and it affects everyone. Staying in the wrong relationship ultimately only reflects what you really think of yourself. So does working on the right one.

First published in the Guardian Family section on 26 April 2013.