Emotions are bad for trading in the respect that they can distract you from making good trading decisions. Therefore, we have to make sure to not be distracted by them. I feel we can achieve that by using the following:
1. Discipline yourself, if you lack discipline - step out from forex, this is not for you.
2. Accept that losses are part of this job, if you can't accept it - you will get crazy and will start posting topics like how to control my emotions.
3. Build a strategy and improve - improve without making it overly compliacted.