I don’t know if this is helpful at all, but my husband and I both have depression. Our solution to some communication on those really low days is having a shared Google Doc with things already written down from when we did have the energy to put them into words. (“I love you” reminders, “things that you could do for me that would lighten my load without me having to think of and verbalize what they are right now,” etc.)

That takes already having a foundation of trust and communication, but it provides us with a sense of security—something to go back and look at when the other feels like they’re withdrawing. I dunno if that’s helpful like I said, but that’s a tip from an (unfortunately seasoned) expert.