The only thing that I can think of is by just go out and looking for a other hobby that is going to help you for sure if you manage to find the right one for you.
If that does not help then you will have to get some help from a professional.
I guess that is the primary concern that OP is facing right now. It is very easy to say that you have to go out and find another hobby but the problem there is how he is going do to it because in reality it really isn't that easy.
Yup! it is not very easy indeed in dealing with addiction, if he would have just direct being addicted to it in any hobby he would be addicted in exchange with gambling he would probably do so but I think these kind of addiction is very hard to get rid of his system when he is already sink to deep in it, a proper way is to consult a psychologist or psychiatrist in giving you suggestion in what to do.