Hi
I'm sorry, it is exhausting dealing with the behaviours, are you taking time out for you, self care, it's important we do so. I find practising mindfulness helps.
My 28DD is a quiet borderline, she is just completing 12 months DBT, what I have learnt is to practise the skills and lessons daily to stay in recovery, daily management of going forwards, yes I/we know there will be bumps and she'll have to work even harder to get back to baseline.
Your DH responded well to therapy 4 years ago? So he knows the score? How long, what kind?
Have you used the tools to the right of your screen that help us communicate better with our pwBPD?
Here is a link - S.E.T (support, empathy, truth statement) may help you.
https://bpdfamily.com/message_board/index.php?topic=69272.0WDx