Could I have done more?

My husband has just walked out on our marriage and very young daughter because he cannot do it any more, HE is not happy and HE wants a life. 

He has always dabbled with online bets the 8 years I have known him. But as you get to know someone you can see that this “fun hobby” is getting a little bit like an obsession. He binge bets, every now and again he can’t help in self and blow £10-40, over 18 months he spent £2,000. He was unaware how much and thought I’d shocked him but then he bets again. Every time I find out we have an open discussion, he promises that he can stop as he isn’t addicted, and I compromise and try to support him (budgets), as I committed to our marriage and family. Last year he said he  would work hard at it and I could have his bank cards and check on him and he deleted the apps as long as he could go poker round his friends once a month (was I enabling him by compromising and agreeing to this?) I didn’t control the finances and take his cards, I decided to trust him again. I said I would check the account every now and again. Now he just said he agreed because he thought it was the right thing to do but he isn’t happy with the terms. He bet again 6 months later, but this time his excuse was it wasn’t football it was poker, always pushing and justifying. We talked again and he banned himself for 5 years and didn’t realise he couldn’t take it off. He went out to buy a new device and again lied about it until I called him out. How can someone lie so much and not realise they have a problem? How can he just throw away all of his responsibilities now and break my heart? He will not back down (I am also stubborn) he won’t get help or even have marriage counselling. I feel so worthless. If the situation was the other way around I would never have done this to him. It’s all about his happiness, his terms, he is normally such a lovely thoughtful person, he has lost his character and said he doesn’t love me and his head can’t go back. I don’t know what to do, I am so lost. He gets so defensive when I bring up the gambling, we just go round in circles. I’ve pointed hi in this direction and he had a chat but said they just told him to ban himself and he already has and it didn’t help. 
He isn’t thinking about how this impacts his daughter, just demanding to see her.

could I have done more?