If he's undergone such a personality change, I would hazard a guess that this is a product of depression. It can really skew how you see loved ones. When I get very low, I become very emotionally detached from people around me. People think that depression is all about being hyper-emotional, but it can also be the other way around. I get to the point where it seems my brain has just shut down--I don't feel anyhjng for my kids or husband. I find this really distressing as I know I should feel something, but I'm just empty. I think it's a type of self-preservation, where my brain jus gets to the point where it can't take any more. I can promise you that the feeling and my normal self comes back once I'm better. I always feel the most incredible relief when I hug my girls and I actually feel the love for them inside.
Is this the first time your DH has been depressed? I know when I first became ill (at first it was PND and six months later I was diagnosed with bipolar) that it was very confusing and I didn't have s clue what was happening to me. Everything I've said above about how the depression affects me is that I've been through so many episodes that I've learnt how to deal with them.
I think having someone to talk to who understands depression and can help your DH understand what's happening and develop coping strategies. Because I am considered to have a 'severe and enduing MI, in under the community mental health team. I see the consultant pdoc and have a community psychiatric nurse (CPN) that I see. Having a CPN is so helpful (providing their good at what they do). Having that professional support and an opportunity to share how I feel makes a huge diffenerce. I know some GP practices have a CPN I don't know whether this might be a help? They can be very good at including partners. We were offered family counselling when I first became illnot sure whether anything is available to you?
Services are so stretched at the moment that sometimes you need to be an advocate who can speak up and demand support and attention. If you drift through being depressed and don't shout up and stamp your feet, services will often just let you continue suffering. If things don't improve for your DH, push for a referral to a psychiatrist. Many GPs have a fairly basic understanding of how to treat MI and will often only prescribe ADs, rather than considering other options/additions.
Finally (& I hope this isn't the case for you), I tried a number of ADs when first diagnosed with PND. I just wasn't getting betterin fact, I was getting worse. Then I was diagnosed with bipolar-I had never had any depression before, but it seems that the bipolar was triggered by hormones and the antidepressants. If you get to the point of trying 3-4 antidepressants and they haven't helped, your DH needs to be seen by a psychiatrist. He shouldn't have to stagger through lifehe can get betterbut it seems that those who shout loudest get the support. Those who are too ill or don't have anybody to demand better care are left behind.
Sorry for the essay! Hope some of it is useful.