this usually happen when you lose money, lose too much , have high hopes of winning. no one wants to lose so its not bad to feel remorseful after that. when this repeats itself too often then it can mean that such person is not gambling responsibly. its good not to gamble with any money you cant afford to lose. this is easier said but might be difficult that is why you should set aside a percentage of your income for gambling like 5% and never go beyond that.