ROE - thank you for that explanation and the reassurance. I'm really sorry you had to endure all that. That sounds horrible, and I can't imagine how stressful that all had to be for you.
Thankfully, my partner doesn't destroy my belongings or harass me at work (he used to send hateful texts and emails, but he has stopped that). As childish as this sounds, I once "returned the favor" by blowing up his phone while he was on a business trip by sending him dozens of photos of us being happy, or the kids birthday parties, or the flower garden. Finally he responded with "What the hell is going on? I've seen all these! Are you trying to send these to your mother?"
I replied "No, I'm showing you what it feels like to get bombarded at work. But I'm too nice to send you hate mail. Still stressful and annoying, though huh?"
He never harassed me at work again.
He indirectly affects my work by keeping me awake at night or making it difficult for me to manage the house by not helping at all. When he's happy, coming home from a stressful day at work is like an oasis. When he's dysregulated, showing up for stressful day at work is like an oasis.
Yes, that's how I am staying sane too. Focusing on what I can do to have a positive effect. I can't control his mood swings, but I can continue to do well at work and look out for myself.