Understood. Same situation happens here.
She is stressing and looking to warn you and or some part of herself. She needs support to bounce validating reassurance back to her.
The trick and its hard, is validation of her feelings of distress.
She will come in an wake me if she is really on tilt. At that point the cleanest way out of the situation is to validate validate validate.
Empathy is the key.
At night you can only validate.
So many good points and SO similar to my situation. I wish to God I had known about BPD and had any of this knowledge before she split and we were in divorce mode...
In my situation, I have (I now know) about the worst job in the world for my BPDw. I travel for about 3-4 days every 3 or 4 days, sometimes go to nice, fun locations, etc. I used to joke with my wife (long before even hearing of BPD) that I could set my watch to her spinning the night prior to me leaving on a trip.
She would be laying in bed next me and I could just feel the tension; the anxiety. I could feel it and I could sense it in her body language and movements. Finally, when she couldn't take it any more, she would blurt out something random about way earlier in the day, like, "earlier today you said xxxx. What did you mean by that?" I'm trying to wind down, really have no idea what she's talking about. Most times it was some random statement in casual conversation that I didn't even remember mentioning. It's like she just wanted to fight. Again, long before my awareness of BPD, so how did I respond? In the worst possible ways mostly! I would quickly get frustrated, imply (sometimes fairly directly) that she's being ridiculous - the antithesis of the validation she was looking for. In fact, she was looking at my leaving as abandonment and looking to lash out and cause me pain to prevent the pain that, in her mind, was headed her way. Many times, when I'd have to get up at 0500, we'd still be circling at 0300 - exhausting and totally made way worse by me and my total lack of understanding or ability to cope with, what to me, was total made up nonsense. Now I know better.
I now know the absolute fear and anxiety she felt every time I left and while I was gone - we would argue over the phone often while I was gone as well. And then I'd get home, things would mostly be great, and then the cycle would repeat in another 3 or 4 days most of the time. Sometimes she would skip a cycle; maybe we'd go 7-10 days, but never more than about 10 days without a blow up.
Having said all that - and really believing I have THE worst career for a BPD spouse - I can get really depressed that I didn't have a chance to adjust my behavior before the split and protective order (good God...), so I can't even talk to her... However - and it's a big however - I really believe the end result would be the same, because with her huge insecurity issues, neediness, anxiety, me being gone all the time, and BPD having a propensity for infidelity, I really believe problems would have developed regardless.
I hate to even think it as I have never cheated in my life, never would, and loved my BPDw with all my heart and soul, looking back now, I wouldn't be surprised if she had - and it crushes me inside thinking about it. At the very least, I'm almost 100% certain she emotionally cheated on me - talking to other guys that I did not know, etc.