Some people are more prone to negative emotions. This is called "dispositional negativity."
Mindfulness is about paying attention to what is going on in our minds, our bodies, and the surrounding environment — and doing this in a kind and curious manner. The meta-awareness and the non-judgmental manner that characterize mindfulness are great tools for any habit change attempt in our lives.
If you consider yourself to be high on dispositional negativity, perhaps the most important thing to know is that it is possible to change. Although it’s not easy, it would probably be one of the most impactful things that you can do for your happiness and health.