Indeed, many traders cannot control their emotions when they are too focused on profits and do not want to accept the losses they have experienced. They think they have to trade again immediately to return the money they have lost due to losses. In fact, it would be better if after experiencing a loss we had to take a break to calm our minds and then start to re-formulate our trading strategy when our minds are calm. We really have to learn to accept defeat and also have to learn from defeat. Usually emotions cannot be controlled in trading due to a trader's lack of insight and experience.
Its very easy to say then to do but you're correct, when we lose a trade we shouldn't start a new trade, we should give it sometimes to rethink and put our thinking together properly because some reason why we lose when we're trading is because we're not in our right senses as we might be dealing with some emotional problem that might affect our right decision making. Many individual has emotional problem but they don't admit it which make it difficult to solve.
Putting your trade on an automatic mode can also help you control your decision, if you know you're having a problem changing a decision you made when you enter the trade, you can set stop loss or take profit so when the market gets to those prices, it does it automatically.
It is true that controlling emotions in trading sounds easy to do. But yeah, this is even more difficult than learning the analyzes in trading. Because emotional management in trading cannot only be studied through theory. But this involves a person's psychology. So it takes more than just theory. But it also takes experience to control emotions.
But yes, one thing that a trader must have if he wants to improve his emotional management is that he must realize his own mistakes. And he must realize that he does have difficulty controlling his own emotions. And if someone is not even aware of this. Then he will not be able to learn from experience forever.