On that, you are very correct @LUCKMCFLY.
I do believe that emotions is something that will always arise no matter how one tries to control it but one good way to control it is to have a set up rule that the gambler must follow, like the aspect of controlling how much that the player is willing to lose, just as you said. I think if a player do write down those rule and always read it out loud to themselves before going to the casino, it could help.
The thing is that many times since I started in casinos and in this whole world, I was a person who played a lot of dice, and I applied many strategies, of all kinds, searching and searching many on social networks , YouTube, among others, I even came up with them myself, also in this context things were going well , but there were moments where I consistently lost, and I even thought that the casino was cheating me, although I didn't understand many concepts , But Among all this I learned that the best thing is to always control what I was going to bet, that I was not Going to run out of money , that was the main thing for me.