I can understand the feeling of wanting someone who is mutually obsessed with you. Maybe there's a special concoction out there where both parties are consistently on each other's minds but they check their own unhealthy/toxic behaviors and respect each other's boundaries. Honestly this seems quite achievable with a bit of mindfulness and management of one's own thoughts and feelings.
Beyond all of that, you seem like a godsend. I understand it can feel manipulative and shallow. I also know that you're improving your life and the lives around you. I believe the falling out of 'love' thing nearly happens to everyone. pwBPD just are more attuned to that. The difference is they blame it on the disease. The reality is it could be a multitude of things that cause people to drift apart. A relationship takes proactive work to keep it fresh.