I (30F) have BPD. No treatment except for the few therapist visits where the therapist mostly diagnosed me with BPD. 

I’m sorry about the length of the post and thank anyone that takes the time to read it. 

The significant romantic relationships I had ended calmly, with both of us realising we weren’t right for each other. I’ve mostly felt sadness for a few days and then moved on fairly quickly. 

More recently I fell for someone in a way I haven’t before. Our relationship was mostly over the phone and long distance (so we haven’t met), so when he stopped feeling that way towards me, I was very surprised to find now I haven’t been able to let it go. We decided to stay friends, and I really value that friendship and the openness we have. Over the past 4 weeks he’s become cagey and stopped responding as much. I understand this to mean he doesn’t want to speak as often anymore and is prioritising other relationships and things in his life. He often leaves me on read, and doesn’t respond in full. In the past I would let this relationship fizzle out naturally and just be happy with the infrequent, superficial contact. 

This time, I’m going from wanting to cut off completely, to hoping I can get him to talk some more and salvage the relationship. The way I feel cycles wildly everyday and I don’t know which part of my mind to believe!

I haven’t ever started to hate him (or split in any way like I have with other people close to me). This is the first person I’ve sincerely just loved, and even though he doesn’t want me, he’s sincerely one of the best people I know and that hasn’t changed, even though I’m also angry sometimes. If I cut him off I’m worried I’ll be doing it out of impulsivity and will regret it. I usually feel like it when I haven’t heard from him for a while. But on the other hand, with every passing week I’m seeing his interest in me disappear and I just want that feeling (indifference, rejection, abandonment?) to stop because it’s interfering so much with my life.

How do you decide what to do when your emotions cycle like this and you can’t even trust your own feelings? How do you cope? And how do you get over someone?

TLDR; going from romantic relationship to friendship. Emotional cycling so much I can’t decide whether to hold on or let go. Any advice welcome