I wonder whether you've ever come across Al Turtle's writings about marriage? He has an extended essay, "The Map of Relationships," available on his website, which explains more fully than anything else I've ever read where relationships go wrong, why people divorce, and what a truly healthy M looks like.
I think that considering his insights might bring you to a new perspective about bonds, dependence, etc, in a M.
You stated, "Boundaries mean that we will only move within that defined circle to keep a relationship going." I tend to think of boundaries, rather, as being for each individual, and maintaining ones own boundaries as being more important than pleasing someone else. If your partner cannot accept your boundaries, then you're diminishing yourself by settling for less to maintain a R. Relationships and freedom, ideally, should be perfectly compatible.
I know you're identified yourself as going around in circles, or getting caught in a pattern of loss & acceptance that's "so far mostly going down," but I see it more as an uphill movement--you've grown so much in strength and wisdom. Al Turtle also points out that people only learn to change through suffering ... which makes our position here, in a weird way, a kind of gift.
