[Meatex]

If this has happened a lot many times then you gotta start taking off the kid gloves
When you see an opportunity where he is listening you gotta step up and make him give you and your mum control and don't take no for an answer - don't get into a yelling match just do it
He has to understand its not his choice until he has the willpower to make the right one

There will - or may have already - come a point when talking won't help and you'll have to take action and be firm. Make him choose between his family and his gambling. You probably won't want to do that but you should understand that it may indeed to come to that point. You have to be willing to throw him away for him to understand his desire to stay and realize what he must do.