I could have a shoe store full of dropped shoes.
SO relatable. You phrased that really well.
In our case, my husband's kids' mom has BPD traits (and she's married to a guy with NPD traits, yay). The kids are 14 & 16 and don't really have BPD behaviors (beyond the "fleas"), so while it's not the kids setting me off, they often "import" conflict and bat-sh*t crazy stuff from Mom's house. It's Friday so the kids will be with us this weekend, and if I weren't numbing out, I would feel massive anxiety as the day wore on, wondering what I was going to go home to. It could be totally fine, or it could be a total meltdown with "You can't make me, I'm going back to Mom's, I'm not going with you, I'm not doing XYZ, I'm walking back" etc. So many Fridays I stay late at work because work is more predictable. Everyone else is "trying to leave early" but not me.
The constant unpredictability wears on us physically, as you're experiencing. The hyper-vigilance makes a lot of sense -- like you always need the adrenaline to be pumping "just in case" you have to deal with something. I often feel like I have to be ready to be super-supportive of my DH, and what that takes is numbing myself to the huge anxiety and "wound up" feelings that I have. It's not healthy, I recognize that.
I think this is a result of feeling I need to be hyper-vigilant, always on call and there for my daughter.
Remind me, how old is your D? And is she still living at home?
I wonder if in your situation, you feel like if you weren't "there for her", that "worse things would happen to her"?
Many parents here will experiment a little bit with "helping less". Sometimes the most "helpful" thing to do is to bite the bullet and start "helping less" so the kids can learn to help themselves a little more. Is that something you've tried, yet?
Another thought is that it is really hard to help other people effectively, when we're depleted. Sleep deprivation is no foundation for thoughtful help. I wonder what would happen if you said to yourself "you know, I want to genuinely help my D, and the best way for me to do that is to model taking care of myself, so I can have resources to be wise in how I help her... tonight, I will put my phone on silent from 10pm to 6am and trust that long term this is helping her more..."
And you could try that one day at a time. I'd be interested to hear your thoughts on that.
It's really hard to pay attention to and then care for our bodies when we are overwhelmed, so you are not alone.
kells76