most people find it very difficult to control thier emotions more especially when they lose a huge amount of money, they can decide to set a limit on when to stop. But at some point they will find it very difficult to stick to thier decision as a result of not gambling with what they can afford to lose, I think this is the major reason why most gamblers always find it very difficult in sticking to thier decision when gambling.
But they must keep try to control their emotions no matter if that is hard. They need to start learn self control so they will not follow their emotions that can lead them to get more losses. In their lesson, they will learn about take a deep breath or other things such as leave the casino right away after they lose so they can reduce the tension. Leaving the casino will be better for them to control their emotion and rest for some time to calm down their emotion. But if they feel they still think about gambling, they must do something that can makes their brain think and distract about gambling.