Help dealing with BPD mental illness

I was diagnosed with BPD (borderline personality disorder) in 2018. As a person with BPD I go through intense emotional mood swings, horrible spending habits in order to feel somewhat “whole”. As a person with BPD too, I felt like I was never my own person. I never felt like I was a “full” circle. I felt as if I was a half. I have toxic attachments to people. In my relationship I constantly feel fear of being alone or left and it gives me a disgusting feeling in my throat. As a person being diagnosed with BPD, how do you manage extreme emotional swings?

What are some things you can do to feel like you are your own person? How do you ease the that lingering fear? Most importantly how do you slap yourself into reality and think more with your mind