I'VE been married for 18 months and, initially, I was very happy. But over the past six months or so, I've become convinced that my husband has been having affairs with other women. It's been driving me nuts; I'm at home most of the time because I no longer work, so now I drop into his office at different times of the day to check up on him.

I usually apologise and say it's because I miss him, which he's accepted in the past, as he admits that he works very long hours - sometimes over the weekend too, if there is a big project to manage.

It all came to a head last week when he caught me going through the call log on his mobile phone. He was angry at first, but when I burst into tears, he realised how upset and worried I was. I eventually told him about my fears and he did all he could to reassure me. He said that he loves me and only me, and he also promised he's not been seeing other women, but somehow this still isn't enough. I really do want to believe him, but a part of me just can't let go of this. It's not as though I have any proof, so why can't I trust him? – AT

Fiona says: Could these feelings stem from a personal insecurity?

In the absence of any proof to back up your suspicions, and given his assurances that he has been faithful, it's not easy to identify obvious causes for your feelings. Perhaps then, your insecurities stem from you, rather than anything your husband might have done? Such feelings can arise for any number of reasons and a common cause is a lack of communication. Given your husband's long hours, this could certainly have contributed to the way you feel.

If you've not had a chance to talk about your new marriage and any stresses or worries that this might have created, it's no wonder that you've started to feel insecure. Another alternative is that your feelings may stem from something in your past; perhaps from an insecure family environment while you were growing up? Or perhaps a relationship in the past has failed because of an unreliable partner, or someone has treated you badly. Any or all of the above might also have dented your self-esteem, which in turn, could generate yet more feelings of insecurity. Whatever the cause, though, I think it's important that you try to resolve these issues. Left unchecked, your feelings could develop into jealousy or even paranoia, which might have serious implications for your marriage, so please consider talking to a Relate counsellor (relate.org.uk) - preferably with your husband too.

Finally, your letter hints that you do not work, so I assume that outside of the demands of the home and in the absence of children, you have plenty of downtime on your hands. I don't mean to point this out unkindly, but simply to illustrate that lots of free time gives you scope to worry, so please consider developing new interests out of the home.

What you decide to do is entirely up to you; it could be further education, voluntary work or simply meeting friends regularly. You might also consider going back to work. You don't mention why you stopped, but if you don't feel as if you have a purpose any more, this could contribute to your feelings of insecurity and lack of confidence.

Should I confront my daughter's harasser?

MY daughter has been having a problem with the wife of one of her colleagues. This woman has, on three occasions, confronted my daughter at work and accused her of sleeping with her husband. She's also called at her flat a couple of times and been very aggressive.

Despite my daughter saying that she hardly knows the man, she has threatened to really hurt her if she doesn't stop. My daughter doesn't want to make a fuss, but is clearly frightened by this woman, so much so that she is already looking to change jobs. I'm so angry that this woman has forced this upon my daughter and wish there was more I could do to help her. Should I confront this woman? –

CL

Fiona says: Encourage your daughter to ask for help

I am not sure that would help as it flies in the face of your daughter's wish not to make a fuss. Further, it puts you in harm's way if this woman gets violent. Having said that, I also think that this woman should not be allowed to harass your daughter further. Talk to your daughter and encourage her to speak to the colleague in question and ask for his help.

It may be that he is having an affair with someone and his wife has jumped to the wrong conclusion as to who it is. I think she should also contact the police and ask how best to proceed. Stress that this isn't making a fuss, it's simply a sensible precaution. In the meantime, advise her not to engage with this woman should she confront her again. She should also keep a record of what is said and when, and where it occurs.

I'm in my 40s and feel like a failure

I'm 43 and I feel that I've never achieved anything in my life. I've got no friends and have drifted from one job to the next, never enjoying any of them and never progressing. If anyone asks me what I want to do, I have no answer. I've never had a lasting relationship and my last girlfriend left me saying that I was boring. The sad thing is, she was right - I never have anything interesting to say.

Other people lead such exciting, interesting lives, whereas I struggle to get from one day to the next without throwing myself under a bus. You probably think this is a bit melodramatic but it's how I feel. In fact, I don't even know why I am writing to you, it's all so futile and then you die. – AM

Fiona says: It's not too late to make a new start

I suspect you wrote to me because, no matter how bleak things appear, some part of you is looking for a way to turn your life around - and it's not too late to start. As a first step, please consider seeing your doctor, as your negative outlook on life could be due to depression, a very real mental illness. The good news is that it can be treated with medication or counselling or a combination of the two. If depression isn't the cause, the doctor will still be able to suggest other ways to help you.

Meanwhile, if things threaten to overwhelm you, or you simply need someone non-judgemental to talk to, the Samaritans (samaritans.org) are always available to talk on 116 123.

Should I tell my ex that she's ruining her life?

I'm really worried about my ex-girlfriend. We were together for a good few years and when we split up - so that I could follow my career abroad - I know it hurt her a lot. She recently sent me a friend request and, when I saw her picture and profile, I was really shocked. She's got incredibly fat and seems to have given up her job, which I thought she loved.

It looks like she now spends most of her day pottering around the flat she shares with her new well-to-do girlfriend. Apparently, they are thinking about getting married, but I can't see it working because she has so little else in her life. We haven't spoken in a while, but she seems to be ruining her life and I really want to help her get back on track. Should I reply to her friend request and tell her so? – PH

Fiona says: I don't think that's wise

If the tables were reversed, would you welcome an ex-girlfriend that you hadn't spoken to in ages commenting on social media that you're fat and ruining your life? I think not! If you genuinely have her best interests at heart and want to re-establish contact, then I suggest you respond positively to her friending approach and take it from there. You should be prepared to be supportive rather than negative about her weight and the choices she's made. If you can't do that, then it would be better to ignore her request and leave her to get on with her own life, much as you are.