Neither should you confuse this with running away from your problems. It is true that facing your problems is the best way to overcome them, but in the case of handling a narcissist, the problem is not yours to overcome; it’s theirs. You are in no way capable of tackling the issues and so you shouldn’t feel guilty by running away from them.
At the end of the day, a narcissist is not a healthy companion for anyone, and the best thing you can do is to try and remove them from your life and move on.
If, for any reason, going no contact isn’t a viable option (perhaps you have children with them, or they are your boss), try to implement the Gray Rock Method to deal with them in a way that will put you at the least risk of getting hurt.