In healthy relationships people have healthy boundaries with each other. Each person is an autonomous individual and has his own identity, thoughts, feelings, opinions, and agency to make his own decisions.
In an enmeshed relationship the boundaries of the two people overlap. There is very little separateness.
In this type of relationship one person tends to believe that he has a right to define, dictate, and control the other persons identify, thoughts, feelings, opinions, and agency.
In the case of the enmeshing parent, the child is defined by the parent and the parent believes and behaves as if what the child does is about the parent. The child is taught from birth that his purpose is to be a reflection of and serve the needs of the parent. The parent has no problem believing that his childrens role is to reflect him.
The relationship is very parasitical. The parent is the parasite, feeding off the child. The child is mind-controlled into believing that his purpose in life is to exist for the parent.
Think about that for a minute. Isnt it really the parents job to be there for the child, raising him to be a strong, confident, healthy individual? In an enmeshment situation, the child is raised to serve the parent and anticipate the parents needs. The parent doesnt concern himself with the needs of the child, really. Yes, he may feed and clothe his child; but, this is often because he wouldnt look very good as a parent if he didnt do the most obvious of parenting activities.
When a child grows up in a home where one of the parents is enmeshed with him the child grows up without his own identity, lost, and confused about who he is. He feels responsible for his parents emotional well-being and takes on the roles of meaning-maker and emotional-caretaker to the parent. In this type of environment, it is very difficult for the child to develop a strong sense of self. He has been trained to be who he is in light of who the parent needs him to be.
When the parent feels upset the child believes he is responsible. He feels guilty and compelled to figure out how to make his parent happy.
The child grows up with an inability to have a personal identity because his vantage point for all decisions are externally defined. The child has been intrinsically trained to search outside himself for his choices. He has no idea how to self-reference.
Because the parent raises his children with a selfish mindset, the child receives no real guidance for life. The child is left to figure out his own way. The parent cant be bothered with teaching the child how to navigate his own way because hes too preoccupied with self.
Since the child is raised with dysfunctional and permeable boundaries, he hasnt learned how to develop healthy boundaries necessary for himself to live well in the world. He will most likely fall victim to other predatory types of individuals because he hasnt learned the value of himself or how to protect himself from others who cross into his personal space.
Further damage occurs because when you grow up with a narcissistic parent you learn that love is conditional. This causes you to walk on eggshells because your worth is constantly at stake.
How to heal from growing up with an enmeshed parental relationship:
Learn to self-reference. You do this by checking within yourself and seeing how you feel. Notice how each decision you make causes you to feel. Determine to make a decision based on what you want, not on what anyone else wants. This is hard because you are scared to death that you are going to get in trouble for not pleasing your parent. But in order to grow you have to learn how to master the skill of self-referencing.
Set personal boundaries. This requires you to learn what you are and are not responsible for in relationships and what you will or will not allow others to do to you. You may have a tendency to feel responsible for other peoples feelings, but train yourself to realize that other peoples feelings are their responsibility not yours. This is a boundary.
Value yourself. Children with narcissistic parents do not value themselves at all. This is because their parent(s) have objectified them and caused them to feel a lack of intrinsic worth. When you are raised from birth to seek your value outside yourself, and the outside source is a narcissist, then you are pretty much doomed to have a low opinion of your worth. In order to heal this, you have got to start treating yourself differently from how your parent(s) treated you. You need to be kind to yourself; be patient with yourself; eliminate negative self-talk.
Re-parent yourself. Since you didnt grow up with a healthy set of parents you were raised in a manner that was insufficient for healthy development. In order to heal this, you can learn how to re-parent yourself by using imagery. For instance, suppose something happens and you notice yourself feeling guilty or responsible or shameful, or some other negative emotion from your childhood. Instead of acting on the emotion or berating yourself for it, learn to treat yourself in a way that would bring healing to your inner child. See next step.
Learn to self-soothe. Growing up with a parent that teaches you to be responsible for the parents well-being prevents you from knowing how to be there for yourself. Learning to find ways to nurture yourself when you feel emotionally dysregulated in important. This is most-likely an underdeveloped skill and will need to be learned. Think of ways to take care of yourself, such as getting enough sleep, feeding yourself healthy foods, getting plenty of exercise, etc.
Address your feelings of guilt. Narcissistic parenting has probably affected you most by engendering in you chronic feelings of guilt and responsibility for other people. Learn to notice the feelings of guilt and start telling yourself you do not have to act on these feelings. Just notice the feelings objectively outside of yourself with curiosity. Remind yourself that just because you feel something does not mean you have to act on it. Make a conscious choice to stop taking on the responsibility of others feelings. Remind yourself that you are feeling guilt because you have been trained to be manipulated that way.
Never give up. Healing is a lifelong process and will take time and practice. Keep reminding yourself that enmeshment involves improper boundaries between two people. The way you are going to heal the effects of this in your own life is going to be by setting and practicing the enforcement of healthy boundaries.