Often, negative thoughts are about what happened in the past and what went wrong. A great way to avoid this is by letting go. Accept the fact that this event happened and identify what you learned from it. Remember failing is a great tool for learning and it’s going to happen. There is no way to prevent it. Once you accept this fact, you will feel much happier and less negative about yourself.
It’s important to note that negative thinking isn’t always bad. It’s when you completely forget about the good things about yourself and in life that it becomes a dangerous situation. Thinking negatively is perfectly healthy as long as you know how to identify the negativity and then interpret it to benefit you in some way. Avoid dwelling on past mistakes and take pride in what you can do and you will be successful.