In my opinion, this is a message that would not best be replied to by suggesting he gets help with his gambling, I think it is a message that doesn’t deserve a reply but does deserve action on your part. You are aware (as I was when I read it) that this could be manipulation for enablement, he has done this before and you have helped him out, so not the actions of a man ‘doing something about his addiction’. You can afford the holiday, you have paid for it and I believe you should go and enjoy a gamble-free holiday with your daughter. This to me is a good time to stand your ground; you are not retaliating or being unkind.
I think you hit the nail on the head when you say he appears to be at only one of his lows. Your CG is messing with your daughter’s head and you know that is not acceptable. I do believe he can love his daughter but at the moment he is only willing to show it as far as his addiction will allow and that, in my opinion, is not enough for a 4 years old. To be the father he wants to be and you believe him to be capable of, he knows what he has to do but at the moment he is having his cake and eating it. He is controlling your life when the phoning and the messaging is allowing him to dictate his comings and goings with your daughter and then only when he says ‘go and do your own thing’ do you do it. A large part of recovery for a CG is taking responsibility; as long as you take if for him, he will not make any effort. If he is not responsible enough to be with you at the agreed time then ‘you’ decide what you are going to do. By all means give him 5 mins in case traffic is bad but always be aware that keeping you waiting is a manipulative behaviour.
I understand your reluctance to get things on a legal footing as this may have the opposite effect from that which you want. Personally I think you are strong enough and independent enough to make this through without legal redress but this will always be up to you.
Look forward to ‘seeing’ you tomorrow evening. Don’t worry, you will get there. I wouldn’t understand you if I had never made mistakes – and I do understand you.