If you're in a relationship with a narcissistic person and you realize that their behavior is affecting your mental health and well-being, the first step to distance yourself is to set clear and firm boundaries. Make sure to communicate clearly and directly what you are willing to tolerate and what you are not. If the person doesn't respect your boundaries, it's important to take measures to protect yourself, such as seeking emotional support and considering seeking professional help. Remember that distancing yourself from a narcissistic person can be difficult, but it's an important step towards recovery and emotional well-being.