Others have offered loads of practical advice and you're obviously on the case here.
So, my point is more focused on how you cope with it from a domestic point of view.
I have a huge amount of sympathy with you.
My husband and I have similar problems - he spends money like water, I wake up in the night panicking because we just get constantly poorer (more and more debt)in spite of having a reasonable income.
But, whilst your husband's behaviour and attitude are unfair and selfish, from what you've said and from my own experience, I think the worst thing you can do is keep pointing this out to him, keep showing him your resentment. He is much more likely to go into defensive mode and the arguments to just spiral.
If you could you try to calm things down between you, by swallowing your resentment (or at least trying not to let it show) and sounding positive about sorting it out together, you may be able to get him back on side, so that he feels as if you are both sorting stuff out.
In my experience, if he feels good about himself (or at least not totally shit), he is much more likely to contribute properly to my plans (especially if he doesn't think of them as just my plans that I am imposing on him, but rather as ours ).
You don't have to pretend you haven't been/are not angry about his behaviour. You can acknowledge this, but say that you don't want to be angry anymore, you just want to get things sorted and pull together on it.
I'd ask him to accompany you to any meetings with CAB and the like - by saying that you value his opinion and need his input too. Try to make him feel as if he has something to contribute and is not just being constantly punished for being out of control of his situation, otherwise he may end up resenting you and not cooperating in the financial plans.
That's just my opinion, based on how things work for my husband and I - obviously I don't know either of you, so I could be wide of the mark, but it may be worth a try.