When it becomes difficult for someone is addicted to gambling to quit. I think its not just about quitting gambling he has to do, if he as any other thing he is addicted to he should first quit on those ones because quitting those ones might make him lose interest automatically in gambling.
I understand your point perfectly well OP, it is like when you are addicted of something, there is every tendencies that you can crave for some kind of habits which might likely be comfortable with that of your already addiction.
And at your point of fighting it out, you will need to accept a possible change from the primary addicted habit before you can be Abel to tackle the secondary.
But relating this fact to gambling is what might be possible but it is unimaginable to me instead, what I think will be responsible to nurture a gambling addiction is greed and when you are too lazy to work for your money and think gambling is the means to earn living.
So to be rescued out of this, you must realized labouring such of your expenses on gambling does not worth it because you won't win in a long term instead, you just keep trying your luck and even when you wins, indisciplines will make you lose it all back to the house in a very short time.
So, once you realizes your lapses on that course, you can be able to defeat your addiction.