First admit you need a life style change. You will need to cut out things like hanging out with gambling friends, having a few beers and watching a game etc.
second, come clean with loved ones such as wife or significant others. You will need support. You will not be able to just walk away and carry on.
Third, inform your gambling ring of buddies that you need to make this change. Those that don't understand can be extremely unsupportive and coerce you to go down the wrong path.
You have to be humble about it, not secretive. Being secretive has gotten you to this point.
As as far as GA, I would think you would have the religion thing pressed on you. Everyone there has an addictive personality and many find religion as their next addiction. That and the fact that religion is often credited for their personal improvement so it feeds that vibe. I'm not saying that is a bad thing by the way.
Obviously another channel of focus is required. Maybe exercise. Lose a few pounds and tighten up a bit and draw off that momentum.
I will personally suggest picking up guitar. I have played my whole life and nothing gives me a greater high than playing to an audience. Takes a lot of practice and due diligence which is something you need.
Doesn't matter how old you are, married, kids, single etc. you need a life style change.