I read your comment about how it is more of an achievement to give than to receive love. It was a very thought-provoking remark. In my view, you summed up the central message of the Gospels. In our culture, we hear much about the dynamic of reciprocity in relationships. "Unconditional love" is usually something we are often told to look only to our pets for!
You have spoken about setting boundaries, saying "ouch," and acting to take care of oneself when another's behavior is not loving. These are ways of loving ourselves.
When thinking about "unconditional love" the challenges are evident, and it becomes obvious that it is rare.
Shared interests, emotional support, communication, are "conditions" most people expect. If love is unconditional, it remains present through betrayal, lies, long periods of no communication, severe moodiness, irritability and dramatic divergence of lifestyles and interests. How many relationships hold up under these circumstances? Also, when we love someone's sense of humor, personality, intellect, or any other aspect of their identity, our love is conditional. Does our love depend on the presence of these pleasing qualities, or if the person ceased to be or have all the things that we enjoy about them, would our "love" still be available? So many times, clearly, the answer is "no."
Relationship gurus tell us that many conditions are reasonable expectations. Better to be single, they tell us, than trapped in a one-way relationship. Any lifestyle is better than being caught in the role as somebody's "doormat."
It's a slippery slope, defining where loving someone ends and becoming a doormat begins. There's not a simple, one-size-fits-all answer, I know.
Love is not easy!
I know a lot of people think that relationships depend upon good negotiation of differences and balance of personal power. This, to me, is mechanistic and ultimately people who go this route of end up chosing power over love.