Well, if we take out the diagnostic jargon (borderline personality traits), all your symptoms are suggestive of ongoing stress & difficulty coping with daily demands of life. All this has happened after facing a traumatic experience (romantic relationship falling apart)
This situation is called as adjustment disorder in psychiatry terms. All you need to do is attend regular therapy/cognitive behaviour therapy sessions & if required (note the word IF) you ll be needing a few days of medications to ride over the crisis. That's it!
Next Steps
avoid thinking about 'Borderline trait' diagnosis. unless it's a 'Borderline personality disorder' diagnosis, you should just focus on your recovery
Health Tips
write a diary daily. Helps with ventilation. write about any 2 good things which happened to you on a daily basis. Read your diary entries once every 15 days. see the magic!! Good luck