This is going to be a somewhat tangential comment.
At rehab over 10 years ago, being twice divorced, having spent my entire relationship history searching for a soulmate, and at the time involved in what I refused to recognize as a highly toxic codependent relationship with a borderline, my therapist gave me the following homework assignment — “describe a healthy romantic relationship.”
I wrote that each partner should maintain their sense of self; no one should lose who they are to the relationship; it should be a partnership wherein each person maintains their autonomy; kind of like a treaty between, for example, the United States and Canada — contributions and rules are agreed to but each country maintains its sovereignty--interdependence.
Despite my description, it took me another year and many consequences to see that I was living opposite of what I described and to finally break free of that relationship--to start to find the balance within myself that you talk about.