Narcissists Have Nothing to Give
In most relationships, there is a give and take. Both parties give some and take some. They support each other and help each other. There is a balance. In narcissistic relationships, this does not happen. Narcissistic relationships are totally imbalanced, with the narcissistic partner taking everything all the time and giving nothing. Many people feel this is malicious on the narcissist's part, that they are purposely not giving, that they are purposely withholding love. And that's understandable but that viewpoint assumes the narcissist has something to give in the first place. They don't.
Narcissism is, at it's basic definition, the inability to separate the self from the external world around it. This is why narcissists believe the world revolves around them. In their experience, it does. They have none of the boundaries between themselves and the outside world that the rest of us have. They are like very young children in this way. You only see this failure in really young children and people with disordered personalities. In children it's because they have not matured enough for it to happen yet and in disordered individuals, it's because they didn't either for whatever reason. Everything happens because of them and to them and for them. They are the master of the universe, for good and for bad. Because of this, there is no ability to understand that other people are separate individuals from the self. They cannot appreciate other people in this way. I've said many times that when narcissists look at other people, they don't see a separate individual with feelings and needs and wants and goals, the way non-narcissistic people do. They see a mirror reflecting themselves, either positively or negatively. This is the extent to which they can engage with others: what does this say about me? This is not something they're doing on purpose. It's not like they are choosing to see people the way they are seeing them, any more than you are choosing to see people the way that you do. It's just what it is.
However, because of this failure to separate, their emotions are all for themselves. They really don't have any for anyone else. It's understandable that in a relationship, people want fairness and love and trust and support, but narcissists have nothing to give you. They are focused solely on themselves, because their inability to distinguish the self from the external world dictates that all things flow to and from the self. The self is the world and the world is the self. This is where all their projection and delusional thinking comes from. Even when they seem to be focusing on others, they are not. Examination of their focus nearly always reveals it is the self rather than other people. When they talk about what you've done wrong, it's to make themselves feel or look better, and things like that. You as a person and the things you have done do not interest them in the slightest unless it relates to them somehow. It isn't personal or purposeful. It's just how it is. It might sound like this is excusing the narcissist, but the truth is, it's arguably worse that it's not a purposeful action, because that means this is not something they are choosing to do and can therefore choose not to do. It's just how they are and there's nothing anyone can do about it.
It's important that people understand this so that they can truly accept the situation. You cannot get what you want from pathologically narcissistic people. They don't have it to give to you. It's not because you're asking too much. It's because they have too little. You can't pour from an empty cup. You can't get blood from a stone. They have nothing to give - to anyone, not just you. You might as well ask them to be a foot taller, or fly around the room by flapping their arms. You can stay in the situation if you choose, of course. That's entirely up to you. But if you do choose to do that, be sure you truly understand what you are dealing with. This person will likely never be able to give you what you want - what you deserve. The relationship will always be unfair, you will never be considered, appreciated or respected, let alone loved. They just don't have it in them. Your job will be to carry the narcissist through life, absorbing their negativity, taking their abuse and waiting patiently until they feel like bothering with you - and you must be grateful for the chance to do all of it. Failure to do any of these things the minute - the very second - you are required to do them, failure to be pleased with the crumbs you are thrown or even the suggestion that you have needs will result in dismissal of you as a person and perhaps even being discarded completely. There will be no sympathy, no understanding and no support for you unless they can somehow get something out of it. If you are sick, if you are tired, if you are stressed, if you are a human being who just has bad days, makes mistakes or is ever wrong, you will be punished unmercifully for your failure - and yes, it is a failure to the narcissist. They see you as two dimensional and there is no consideration for you or any understanding at all that you are a human being.
It's like a man driving a horse. The horse is pulling a very heavy cart with bricks in it up an endless hill. He drives the horse day and night, never letting the horse rest or sleep or eat. He whips the horse continually, making it pull and pull and pull. The horse finally drops down dead under the strain and the man stands there scratching his head, wondering what was wrong with that lazy horse. He figures it must have been defective and goes and gets another one which he proceeds to treat the exact same way. When that one dies of the same thing, he assumes he got another bad one and starts over again. This is how pathological narcissists treat people: like they are machines with no feelings. Push this button, the machine does one thing. Push that button, it does something else. Your suffering means nothing to them, except when it relates to themselves. If they can say, "I hurt you. Ha ha, I'm powerful and important" or they can say, "I hurt you. Boo hoo, I'm scum and no one loves me" then it will matter as far as it can be used. Other than that, it's meaningless. Nothing that does not directly affect them means anything to them.
In the end, the ball is in your court. It's a question of what your expectations are and what you will accept in your life. They are what they are. Trying to change them is futile. Trying to make them care is pointless. People can't be forced to feel feelings they don't have and that's just the way it is. They have no choice. They are what they are. But you do. You can choose not to deal with people who don't treat you the way you deserve. Maybe the question really is, what do you think you deserve?