Hi Loobs
I am glad you are having your hands kept full with good things which help stop the bad things taking up room in your head.
I hope the ‘gambling episode’ was just that for you – an episode in your book of life that you have been reading for a long time.   It is easier I think for you to turn the page now because you know the book will continue regardless of the storm in the last chapter.   Chapters with grandchildren and friends will follow on now and lighten your heart.   I sincerely hope to hear soon that your son decides to give himself a better chance in life and embrace recovery.  
It is so sad to hear how much damage some CGs seem to have to inflict on themselves before they realise that the only way forward to is to take the difficult route of recovery and total absinence.   Your son has certainly ducked and dived his way round that path for some time but each hurt he has caused himself does add up.  
I know he can change but he is still seemingly immature.   The fact that his family are moving on, growing in stature and refusing his addiction in their lives, could not be a greater incentive to him.  
I wondered if you were still reading.
As Ever