If you are having 'negative' thoughts come up for you, don't judge them because what is happening is you are creating situations where emotions and thoughts are coming up for you that are allowing you to see where you are still being conditional in your thinking. Conditional thinking causes loss, lack and illness and gets in the way of you creating what it is that you want in your life. This is a good thing because when you become aware of when you are being conditional, you can do something about it.

First, don't judge that you are having these feelings, because if you do, you will recreate them again later. Just allow them to surface and observe them, and be in the gratitude that you have the opportunity to become aware of thoughts that will keep you from having what you want. With this awareness, you will be able to choose differently. Something you can do that will help is when you have these thoughts, just repeat over and over again in your mind,
"Look for the purpose, look for the good", (you can find more about 1 of these 12 keys that will help to diffuse conditional thinking in the moment it occurs using the link.)