How do we regulate our emotions while betting and how important is it?
Above stated are correct. Emotions are normal simply because we are all human. Fear, excitement, confidence, regret and every emotion exist because of expectations. In gambling, you are in fear because something important to you could be lost, and that is money. Same thing goes with excitement of getting something in return, from winning a game. You could be confident of things if you know you are in right assumption. Regrets take place once all these things that you expect are not met. It will always be your expectations on what you are doing. In gambling, what intensifies those expectations? Money. Money creates an enough drive to make things 'big' in particular with the involvememt of emotions in this activity.
Is there a way to control your emotion when you are gambling? Yes, by lowering your expectation and drive will also be lessen. It is normal to expect for profit in gambling and what's not is to put or do anything to get it. Accept how gambling works; existence of the tendency to either lose or win. By doing so, you wouldn't be betting that much. Excitement and confidence of winning will be there as positive emotions but at least the chance of being greedy eventually, will be lessen if you won't expect that much of the profit and loss ratio. Regulating your emotion is simply difficult because it is a normal response with expectancy (stimuli in this discussion). But as I said, you could lessen the intensity of emotions by managing your expectations.