That's the main reason why i lost many btc on gambling i did not control my emotions during betting.
Oh, but if you really want to control your emotions you can do that its not imposible, because you always have a choice to play gambling or to stop playing. If you lost the game, you can stop it and try again to play next day and you can also control the capital amount so that you will not lose many btc while playing gambling. You can control everything if you really want.