Welcome to the forum!
Your situation sounds really difficult, and I am sorry to hear that you lost your mother last year. It sounds as though you are the only support your husband has, not because others haven't tried to help of course. This is a lot of pressure on you as the sole carer/loved one/friend to him. His reliance on you in addition to the hostility and lack of appreciation/outward love must be emotionally frustrating and exhausting. Though you are not the one with mental health challenges, seeing a counsellor for yourself would be beneficial. It's important that you have someone understanding to talk to and seek rapport with. Trying a few sessions is worthwhile.
Does your husband have any mental health support currently? Has he received much professional help for his depression over the last six years? It's crucial that he gets regular treatment, especially because of his suicide attempt. Taking your husband to his doctor (GP) for a referral is a good start (if he's not receiving this help already). This resource is worth you exploring (and your husband working through when he is able to): http://www.cci.health.wa.gov.au/resources/infopax.cfm?Info_ID=37
The Carers Australia website is worth visiting, as there are resources and links that could be of benefit. It's vital that you maintain your own wellbeing as a carer.
It would be great to hear back from you!
Zeal has provided some great advice above and I agree, seeing someone about this can be very beneficial for you, my anxiety caused a drift in my marriage and my wife is now seeing someone as she has her own anxiety which stems from me but she is slowly understanding and responding to my situation and our situation better.
I know your husband won't talk to anyone but has he ever seen a counsellor for his depression? My first thought would be to see a marriage counsellor together to work through your problems and get in a place where it is non-judgemental, I know it is so hard to actually commit to, but for the sake of your marriage it may be an option. I am also sorry to hear about your mum, everything must be piling up on you which is why seeing a counsellor for yourself may not be a bad idea.
My best for you and your partner,
Your husband is denying that he has a mental problem by turning it around and blaming you, so this won't help him and what it will do is start to break you down, which is exactly what has happened.
While you are struggling the loss of you dear mum, this isn't what you want to cope with, but when depression strikes it doesn't matter how talented a person can be because this illness has no sympathy for anyone.
You have to make a decision, and please note that your husband could have another attempt while you are still with him, because this may happen at any time, I hope that he doesn't doesn't, but there have been similar comments like yours with people being in exactly the same situation as you are in, but you have to look after yourself, that's first and foremost, because nothing you say to him will ever satisfy him, so you need to step aside and get the help you need.
By saying this may sound to be very cruel, but that's what my (ex) wife did, she had decided she had had enough and couldn't help me anymore, she needed to regain some sanity, and once the divorce went through and our house was sold is when I started to improve and my depression lifted.
You have to take care of yourself. Geoff.