There's nothing wrong with dating partners who have personality disorders. There's nothing wrong with preferring relational sex over casual sex. There's nothing wrong with wanting to view romantic relationships as having some kind of spiritual journey or personal growth component.
I don't know you. I haven't seen your life. I look at how this thread started and I see this post and I see a pattern and I try to infer something about how you see yourself and how you make decisions. And I see also this:
Reality check: About 47% of American adults are married. Enough of the remainder probably want to be that people preferring to be in committed relationships are probably not a minority. The numbers vary in other countries, but in most of the world people are more conservative. The CIA keeps track of the proportion of women (specifically) who are married by country, which shows similar figures:
www.cia.gov
I'm overanalyzing the point. The point is that it certainly isn't intuitively obvious and in fact it isn't even true that most people see casual sex as normal. What I'm getting at though is
why you would believe this. A person's sense of identity has two parts: what they see themselves as being and where they see themselves as being: the second one is the world they think they inhabit. Who you think you are and the way you distinguish yourself, mentally, from what you see as normal are connected.
The picture coming together is of someone who sees himself as unusually cautious and empathetic in a world of promiscuous and lighthearted people. This isn't a common accusation of narcissism. Sometimes it is just personal history. People get into subcultures as they find themselves in the world and they may find themselves surrounded by people who act a certain way or enjoy certain things that are very different from the actual population median. They can come to see themselves in relation to that background instead of the "average". This is normal, because there is no real environment that mimics the broader world exactly; the world is a million weird little villages.
But my working hypothesis is: you think you are abnormal, even though you are not, and you feel safe with people who are discomforted by the world in ways that you think are similar to the way that you are discomforted by your world. There's an example in this thread: you expected another user to know what "FWB" means, even though they don't. In your past experiences, in whatever libertine milieu you mingled in your underage-drinking years, it was probably normal for people to know that. Not for everyone. For the people around you.
When people repeatedly find themselves dating partners who mistreat them, they are not to blame for those partners' actions. But in terms of raw probability, if you keep finding partners with BPD, PTSD, something else ending in "disorder", it probably isn't a complete accident. Some reflection is indicated.
A person's status quo self-image is sticky, particularly the world they inhabit. Sometimes, it's too sticky, even when they aren't happy with their own world-view. You know, obviously, there are people whose experience of romance is very much unlike your own. But you date people whose world is closed-off. It isn't really like your own. But it isn't calling out to you, either. And because of this, it doesn't challenge
your world.
And that's why I came to think you're holding on to it.
... But jokes aside. I'm very sorry for what you experienced. BPD is a terribly destructive disease including for anyone involved with the person. If it can't be treated successfully you have little options to maintain a healthy relationship. That's just a fact. I hope you can look back with compassion one day and just wish for her best, without getting involved again...
It's never bad to do some self-reflection along the way
