Hi looking,
Welcome to the family. I can hear the depth of your pain and I know this can be a very confusing and difficult place to be in. I've been there myself. Many of use here have. The first step towards calming the hurt can be to learn about what you've been through and what you're going through.
Here are a couple of articles that might help:
https://bpdfamily.com/content/how-borderline-relationship-evolveshttps://bpdfamily.com/pdfs/10_beliefs.pdfCan you tell us a little more about what happened in your relationship? You say you feel alone. Do you have any close family or friends to lean on? You say he won't go to therapy with you. How about going to therapy for yourself in that case? Do you have a therapist?
Seeing a therapist if possible, talking to family and friends you trust, reading and writing here ... .these are all ways that can start, slowly, to lead you out of the confusion and hurt.
Take good care of yourself and show yourself some kindness and love at this stage