Even if you control your self, in the long run you will still lose. That's how gambling works and how the owner profit. The more you believe that when you control your self in gambling you will not lose, the more you will stay in the website and the more you will lose in the long run.
Though some people really believe that there is something at the end of the line in gambling, that's not true, the result of gambling is unpredictable, what is predictable is you will lose money and time there.
If you lose in gambling in the long run even if you have control in yourself then there might be wrong in the way you are gambling. Maybe you don't learn from your previous mistakes and keep repeating them that's why you are not earning any profit from your gambling for a long time. If you know how to control yourself in gambling then you won't let the casino take your money easily. And take any profit from the beggining you win some amounts.