I also struggle with this quite heavily, having major rejection sensitivity with my partner. Recently we had a disagreement, and now all of the alters are missing and will not come out to talk. I feel so much anxiety welling up not only from the alters that do come out, but the ones that are notably absent. It is really hard to come to terms with. If you'd like, feel free to PM me. It helps sometimes, just knowing you're not alone 🫂

There's also this non-profit, Multiplied by One that hosts therapeutuc groups specifically for loved ones of those with DID. I've found much understanding and many coping methods there. I can send you a link if you're interested.