You are right, when someone is stressed or their state of mind is troubled, it would be very difficult to make accurate prediction, in sports betting one can not make good prediction as long as their mind is not settled and therefore they have to be in the right frame of mind before they gamble, unlike slot games which totally depends on luck and you can gamble without any analysis and the results depends on random generator but sport is not same thing and that's what some people do not understand.
I have noticed this too, it is best to place a bet when nothing distracts you and you are in a calm state, if you are emotional, it is better to take a break, maybe even for a few days or weeks, to completely switch to other things and return when you are ready to continue playing without unnecessary emotions. I understand that it is very difficult to earn money in gambling, so I try not to spend too much of my time on it, if I see that I need a break, I will take it.