I suppose that stress in gambling can only be avoided when you completely let go of the thought of needing to win a certain amount, which appears as an image in front of your eyes, and take it easier. Perhaps there are people who can focus on the game and enjoy the process, rather than just the expected outcome. But in that case, I think it's only possible in more complicated games, like poker or certain board games. Slots and dice are definitely not suitable for this because the gameplay in them is monotonous.
Doing that will make you less motivated on gambling since you are decreasing the purpose of why do you gamble which is for fun through experiencing this massive win.
It’s like a dream which we enjoy when it’s exaggerated. The more you dream high the more entertaining it will be.
You only need to use bankroll that you can afford to lose in able to enjoy gambling experiencing too much stress when you lose. Your bankroll size is the only reason why many fee stressful when losing in gambling.