Ok B
Calm down and enjoy your new man – it was another man who gambled before your wedding.   It is common for CGs to not turn up for the birth of their child because they are gambling – it is common for active CGs to lack empathy.
Don’t let this spoil his homecoming or all your dreams.  it is time to let go of the past.
Nothing you would write would surprise me – even if I heard his whole story — he has had the courage to face his addiction. 
He has trusted you by telling you how bad he has been – he will need you to move forward with him