The dilemma I’ve been married for nearly 30 years to a guy who is outwardly kind and gentle. Our grown-up kids left home five or so years ago. Although my husband is reserved in public, he has a bad temper with me and is constantly critical. As he gets older, he seems to become more controlling and angrier. Now in my 60s, I’m worn out with petty arguments and can’t face retirement with him. He is already retired and wants me to do the same.

My way of coping involves having a secret, long-term (and very loving) relationship with a man who lives far enough away not to be a threat. This man has made it clear he doesn’t intend ever to leave his partner and has always been honest about this. I also spend too much on clothes, books and cosmetics to cheer myself up.

I have developed some major long-term health problems and seem to get a new and serious autoimmune condition every few years. I feel like I’m sinking – and my life expectancy is shrinking, too. The criticism at home is knocking my confidence and my ability to escape to work is becoming more difficult with each new health condition.

Mariella replies Time to declutter. I appreciate what you say about your husband and, if his controlling nature and anger are on the increase, now may well be the time to make a break. Retirement can be a petrifying prospect when the person you’ve been enduring a parallel life with suddenly converges on to your path. If you are worried about your safety or feel threatened it’s a matter for professionals. You need to contact womensaid.org.uk who are experts in the field and can advise you.

I’m going to respond assuming your husband’s behaviour is nothing worse than that of a frustrated spouse. I’ve said a lot worse than you accuse yours of about my own… and letters to this mailbox confirm that not every partner deemed controlling means an amber warning. I hope, therefore, that we can work out whether you could be doing anything different yourself.

Is it hard to imagine that your husband is not experiencing a sense of abandonment

It’s easy enough to find fault in a partner we’ve been over exposed to for decades, but breaking up is hard to do and if there’s any chance of improving matters that’s got to be worth consideration. Most obviously you can’t just put your long-term, ongoing, extramarital affair in a box that you keep separate from other matters. We are all past masters at self-delusion, but failing to understand that this alternative relationship might be impacting on your marriage is naive to say the least.

Is it hard to imagine that your husband, while not aware exactly of what’s going on, is not experiencing a sense of abandonment, contributed to by the fact that you are having your needs catered for elsewhere? It might even be why he’s urging you to retire. If I had £1 for every person I’ve met or corresponded with who was in denial about the way their actions might be contributing to their woes, I’d retire myself – feet up, on a sailboat, headed for the South Seas.

I’m not suggesting your affair is the cause of your marriage problems, but it will certainly offer respite and make dealing with them less pressing. If you really are no longer interested in remaining with your husband then looking for a new relationship is one way of facilitating escape. But at the moment it would be impossible to squeeze someone in between your husband and your lover, who has already made it clear he’s not the one.

Maybe it’s just me, but an ongoing affair with someone who would never choose me for anything other than diversionary entertainment is something I’d find hard to stomach. You and your lover seem to be in a union as unexciting as any marriage – a complacent affair. Despite that, you’re blaming your health issues on the man you married. Your lover may have made it clear he doesn’t want any further responsibility in your liaison, but that doesn’t exonerate him from your unhealthy state of mind. You’re both betraying your spouses and not even because you’re blinded by dreams of a future together. Then there’s the excessive spending you highlight.

One thing is clear: you are unhappy and are failing to tackle the root cause in any constructive way. The stimulus for your ill-health may well be your husband’s controlling behaviour, but while you’re immersed in displacement activity, whether with your lover or waving your credit card around, how will you ever know?

I’m concerned that you are suffering from low-level depression, which is making sensible and clear choices impossible. I’d like you to talk to a professional (start with your GP) in an attempt to understand the impulses that are causing your current self-destructive tendencies. A new life and relationship are certainly possibilities, but the likelihood of contentment in any union, until you’ve taken a long hard look at how you yourself behave, is small indeed. Your husband certainly won’t be a benign force, but he may not be the root of all your woes. If you can clear away the emotional debris, you’re more likely to find a path to self-enlightenment.

If you have a dilemma, send a brief email to mariella.frostrup@observer.co.uk. Follow her on Twitter @mariellaf1

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If you are affected by any of the issues in this piece, please contact womensaid.org.uk