Following are a few things to keep in mind to overcome this anxiety:
Know your fears
Multiple sorts of fears are involved when you trade. It is important to understand and figure out what the fear represents. Knowing the fear will make it easier to deal with it. There can be a fear of losing money, fear of missing out on a trade, fear of not making profits, or even a fear of taking a wrong decision. All of this results in high anxiety levels that can be fatal at times. If you know which of these is a concern, it is easier to deal with it, because one is not directionless.
Be cautious about your emotional attachment to the outcome of the trade. Accept that ‘to win, you have to be willing to lose.' Anxiety is only going to worsen the scenario and be of no use. So accept that sometimes you win, and sometimes you lose.
Learn from experience
The motive of a hardcore trader should not be to earn money but to learn. Trading is all about gaining from experience and using it to strategize your next trade. If you go into depression after losing money you willfully risked, you might not turn out to be a successful trader. So, conclude your losses and learn from them to overcome your anxiety.
If you have an action plan, then just have faith in your self. Trust the strategy you develop and trust your calculations. Overthinking about your strategy and calculations is not going to take you anywhere. All you will do is further ruin your game plan and increase your frustration levels.