Certainly, emotions are an integral part of human nature, but even after a big loss, you do not need to give in to despair. You need to carefully weigh your strength and decide whether to continue gambling or stop it. Losing is completely normal, because the percentage of losses significantly exceeds the percentage of wins. Unfortunately, not all people can cope with the feeling of loss and disappointment.
Gambling is never for everyone just like business is not for everyone. These two involves people that has the mind to take risk and accommodate the outcome from it. People who don't rely just on emotion but reality to strike the balance of taking risk proportional to what they can carry. An experience gambler is different from those inexperienced in the field of gambling because they gamble reasonable while the latter does it emotionally.
Those who can't take a negative outcome may most probably not going to enter gambling as they knew they have no appetite on the risk involved with gambling.
An experienced gambler like how you describe it might feel emotional too especially during a massive loss. We all do, no matter how reasonable it is. That's the reason why we have heard stories about gamblers who are in a deep debt taking their lives as they feel hopeless and depressed.