When you start losing a lot of money and in a successiv way you have to know that it is better for you to stop and look for another way to earn money. I think gamblin too is not the best way to earn money because it is based on luck so we have to find other ways to make a good income.
To be honest, it will be very hard to stop when we are in a disadvantage position (lose). This is a problem that for most gamblers is difficult to solve. Self control and limiting the amount of money we can afford to lose may can help but both things will require hard work and can not be achieved in a short time.