Oh boy DC. I wish I could argue with you about any of this, but this is me, too. Completely. I functioned so well before this encounter with my BPDex. Even I thought that was the most I could aspire to anymore. Like you, I know that sometime soon I'll seem to be just fine. People like me, I do very well. Objectively, in a world-historical sense, I'm very fortunate. If you can just overlook aspirations of being united with another person's soul the way I briefly felt I was with this man.
It would have been so much better not to experienced this. I wouldn't have realized what it is that I really still want. Like you, I know it is not just out there around the corner. Which is one reason why it's been so very hard to cut ties and walk away, to give up all hope (malignant hope). He feels very unusual in his ability to meet me in this way.
That's also why it's so weird to see him with someone else (and I'm sure the same is true for you). When we had this sublime connection, how is it possible for him to be with someone else? Any that's where the mind-bending really starts.  :)id I misunderstand? How is that possible? Like you said in another post, our world doesn't make sense when all these things are true simultaneously.
It's not just out there, around the corner.
And this forms part of my (our?) confusion. Fact is, it is almost statistically impossible to walk away from an intense attraction/relationship/whatever and then magically find that with the next person. The chances of this are so very slim for the rest of us that it's laughable to imagine it.
And yet ... .here they are (presumably) feeling the same intensity, the same attraction, the same desires. And the replacement will be hearing those words and feelings that felt like they were aimed specifically at us ... they had to be right? We cannot be so clueless and stupid to fall for vague and generalised proclamations ... they spoke directly and specifically to us.
Or did they?
I tell myself that he cannot possibly be experiencing with my replacement what he experienced with me. It's simply not possible; it has to be different, less intense. Fact that he stays away all week and goes to her only on weekends supports this in my distorted mind - when I have been around, he would take days off work ... sometimes 3 in a row just to lie in bed with me.
But, a part of me knows that he is feeling more for her now than he does for me, no matter what their dynamic is ... and moreover, the space between visits that he gets could actually mean that she and he are more suited ... .that he will be able to keep from being triggered ... .that over time, they will build more than he and I had ... .a warm flame instead of a raging inferno that consumes ... .
My sense-making strategies are entirely absent I have very few facts - those I do have are loaded with my own insecurities and fears ... .the world is purple and unforgiving and somehow on an axis I never noticed before ... .it's not the same world.