Why no credible information on BPD and "favorite person" FP

I'm a mid 40's male diagnosed with BPD over two years ago although it's something I've struggled with all my life. One of my reasons for starting therapy was that I knew that my interactions with my "favorite person" was way over the top. My emotions were governed by how he interacted with me. A failure to respond to a text meant that my world was over, while a positive interaction would send me over the moon! Constant "looping" thinking, obsessing and splitting on him was getting in the way of me being functional. I'm a fairly "quiet" borderline and I rarely express my emotions so I internalized all of this stuff and was slipping further and further away from reality.

I have worked hard on myself in therapy and feel confident in the progress I have made but I'm still struggling with my interactions with my "FP." The interactions now are calmer, my expectations are more rational and I don't fall to pieces if he doesn't respond the way I want him to.

I have a friend who has BPD and her and I have been a great support system for each other because she also has an "FP." Online there are literally hundreds of anecdotal stories from people who suffer with BPD and their interactions with their FP. But I have found NOTHING from legitimate (researched, scientific) psychological sources. My therapist was unaware of the term and even on here I've found very little information.

I believe that having an "FP" is a fundamental piece in struggling with borderline and yet there's nothing that I've been able to find that helps someone with this aspect. Is there anyone out there who knows of a resource specifically designed to help get rid of this FP concept? If you've ever "imprinted" on another person before you know what pure hell it is. I've had great success in the areas of feeling less abandoned, having a stronger sense of self and controlling (and not acting on) erratic emotions but I'm still very much struggling in controlling myself when it comes to my "FP." Maybe it's just semantics and what I'm describing is not termed as "FP" but something else? Any help would greatly appreciated even if it's just how you were able to let go of having an "FP." I have no desire to discontinue the relationship, and I have no desire to change HIM anymore. What I want to be able to do is change MYSELF and my over feeling, cyclical splitting and all the other BS that comes with having an "FP." Thank you!

I don't think the term FP is frequently used. BPDs are more commonly described as having difficulties in interpersonal relationships, or in romantic relationships, or maybe intimate/close relationships. I agree that we might have a certain favorite person who makes our symptoms very visible, but personally I've found that I have the same, but much milder tendencies towards more distant friends and acquaintances. The insecurity is always there, even if I'm not fully aware of it.

Thank you for your response. And you're right, the generalized insecurity that is part of all my relationships is intensified on one "favorite Person." The term is used frequently by the BPD commmunity on [mod edit]