Your practice of mindfulness has taught you that it is not your mental states themselves that make you uncomfortable, but your attitude toward them. You may have the idea that mental states are part of your own personality, part of your existence. Then you try to reject the unpleasant ones as if they were foreign bodies. But you cannot really reject them because they were not yours in the first place. Your best response is to maintain a steady practice of observing the mind, without reacting with clinging or aversion to anything that comes up, but skilfully working to free the mind from all unwholesome states.
Bhante Henepola Gunaratana, Eight Mindful Steps to Happiness