Get mad as fuck at whatever game you're playing and rage bet til your broke seems like a sound strategy right? Controlling yourself from going crazy is what controlling your emotions is all about. You can be happy or sad, but the moment you get angry and start betting out of control you're really pushing your luck and probably going to end up going bad.
I never saw a player get lucky when betting like a madman. On the contrary, I saw players get luckier when they calmed down and relaxed a bit.
Now let’s flip it. Since we allow ourselves to enjoy the wins emotionally, then maybe we should also face the losses the same way.
Happiness in gambling is a feeling that comes only from winning. Nobody can be happy if they lose. Knowing from the start that the money that you bet is gone helps to be a little bit less sad and angry if you don't win. Controlling your emotions doesn't spoil the fun, but it can make it last longer if you stay on game. If someone finds it hard, then better to stay out or gamble less than he usually bets.