I agree to that, better to find ways to keep your mind busy instead of keep allowing yourself to gamble and lose more money, if someone already notice that addiction may already showing on your actions if there's changes that shows on how you treat gambling best to listen and look for any alternative ways to avoid getting to deep.
There are many other things that you can deal with aside from gambling, it's on you if how will you execute your plans to avoid deeper involvement into it.
I think you are right when you say that excessive involvement in gambling leads to changes that players usually notice. At that moment it is very important not to ignore them but to pay attention to them so that gambling does not become something that negatively affects your life and your finances. I believe it is not even necessary to worry about what could replace gambling or to look for alternative activities and so on. The most important thing is to realize in time, that gambling is having a bad impact on the quality of your life, and to stop if that is the case.