Secondary emotion
There is the first emotion. Something happens that causes you to feel happy, excited, angry, sad.
You feel happy, and then you start to feel guilty about being happy.
You feel excited, and then you start to worry about a future time when you'll be less excited.
You feel angry, and then you start to feel even more angry at being angry.
You feel sad, and then you start to feel frustrated because you're sad all the time.
Having an emotion is a reaction to something that happens. Having a secondary emotion about the first emotion turns this into a chain reaction.
When this happens, go back to whatever caused the first emotion. What was it? Okay, that happened. And it caused you to experience an emotion. Okay, you experienced the emotion.
Now, take a deep breath. What has happened has happened. It is what it is. You are now in the present. There is no past and no future.
Now, are you still experiencing the second emotion? Are you still experiencing the first emotion?