You will still be discarded even if you are a good source of narcissistic supply. Narcissists devalue their partners frequently thoughout the relationship. It is a cycle. They devalue you then throw you crumbs to keep you hooked. They grow disgusted at your weakness for staying. They grow to resent their primary sources of supply. Narcissists are addicted to supply not the source of the supply so one supplier can be replaced with another very easily. Narcissists are addicted to the fuel/supply which validates and props up the false self. The source of the supply is no more than an object to them. The narcissist is always mad about something anger, rage, and envy are at the heart of the narcissist. They project, and rage at their partners all the time for reasons that don’t make sense to anyone but the narcissist. They are wounded people and they perceive everything as a slight. When they feel slighted their defense mechanisms kicks in to recover from the wound and they have to devalue in order to recover. This keeps the false self in place. Keeping the false self in place is life or death to the narcissist. It is all he or she has and the false self must remain in tact no matter what harm it brings to others. After the end of the formal relationship they may try to come back at a later date when other supply sources have failed. Do yourself a favor and go no contact.