A trader should follow some specific rules and regulation which he needs to set before start trading. Once he closes the trading on that day he should open it on the next day only, if he keeps on checking the market might feel more stress about the market.
A trader that is not disciplined is not a good trader, which is just the plain truth. It is one thing to have the skills, strategy, knowledge on how to trade, and it is another thing to work on your mindset on the way you approach trading. A lot of people approach trading like they want to make all the money they can make in a single trade, some approach it with emotions that even with their strategies, their ability to execute it perfectly becomes a challenge and so on.
To be able to deal with stress, there are some things you need to tell yourself when it comes to rules on your approach, and how you execute your strategy, because if you do not do that onset, the chances are that you will flop.