Hi Jenny
My CG has always said that you can’t save ‘em all and I am sorry to say he is right.  
You have certainly been led a dance – I felt your highs and your lows as you progressed along.  
The rehab can only help those who really want to change.   You have tried so hard, he has had so many chances.   So much energy has been wasted trying to give him what he said he wanted but obviously he didn’t want it enough.
The focus has now to be on you and your boys.  
This time Jenny – you have to be stronger than you have ever been before.   You are vulnerable – all non-CGs who expend so much energy trying to give their loved one a life in control of their addiction find it hard to really let go.   You have given him opportunity upon opportunity, he has been through rehab twice and still he continues to allow his addiction control of his life.   I cannot tell you what to do, as you so well know, but in my opinion you should really batten down the hatches this time, put the shutters up, jump the sinking ship, call it a day, throw in the towel and any other method of self-preservation.  
It would be great to believe that the addiction had finished meddling with your life but he does appear to be on a length of elastic and I know how convincing he is.  
Jenny ‘if’ he tries to re-enter your life, please use this forum and groups – you are worth so much more than all the rotten treatment you have had.   I will never judge, I couldn’t begin to – I know what the addiction sounds like knocking at the door.  
Some people don’t every get it – we have Twilight’s father to teach us that.   In my opinion you have given enough BUT if you feel any weakening of your resolve come back and talk.  
Healing takes time – it is gradual and exhausting but ultimately it is a walk back to life.   I have had to heal from a few things in my life and sometimes it feels the pain will last for ever.   The only person that can change our life is ourselves and we do it by living for today and enjoying the wonderful things that are in our lives – yes even grotty teenagers.   Recovery can only be one day at a time but the days do add up and one day the thing that we thought would destroy us becomes a distant memory.
By the way if you want to write – ignore the nosey parkers.  Anyone who wishes to turn your story into malicious gossip has never understood what a person has experienced living with the addiction to gamble – so their opinions will never be worth listening to. 
Support others only if you feel ready for it or walk away from this site and know that you have done well – you have been a terrific supporter to many, including me.
I wish you and your boys so much happiness.