Ghosted/broke up with partner during major episode?

I guess I’m just looking for knowledge and understanding about the thinking (or lack thereof) of people who left their relationships during a major depressive episode. Why do it? Why push someone so so so so far away?

I’m struggling to understand what the thoughts are when you push your partner away so drastically during a major episode. How do you know you won’t want their support later? Why don’t you just ask for a break instead of ghosting? How do you go from “you’re the best thing in my life” to “I can’t do this”? Did leaving your relationship make you realize you need help? I love him whether he comes back to me ever again or not. I want him to feel better whether that ends up with a reconciliation or not, so my questions aren’t just aimed at figuring out if he will come back. I feel like I genuinely need to understand the thought process of the depressed partner who leaves so I can tell myself that this is out of my control.

Maybe I’m trying to convince myself that it wasn’t me but it’s the disease of depression. I also struggle with mental health, so this has taken a huge toll on my self esteem and what I thought of myself as a partner. I wish I could have helped him get the help he needs, but I know I can’t make anyone do anything. He has to want it.

I use the term “major episode” because my (I guess ex) boyfriend has major depressive disorder (maybe bipolar) and he’s always some low level of depressed, but the “major episodes” consist of completely isolating, no communication, panic attacks at having to engage with anyone, sleeping for days, feeling numb. His last episode culminated in him telling me he doesn’t want to disappoint me anymore by being unreliable mentally and can’t be in a relationship and isn’t ready to get real psych help because he thinks it won’t work on him (he said he’s defective). He’s medicated but not properly (only sees a general practitioner and is obviously on the wrong medicine). No therapy. He said his piece and then ghosted despite my trying to reach out to offer support. He won’t answer me, so I decided to give him the space he’s obviously saying he wants. I won’t bug him anymore even though I wish my supportive words could help him.

I have depression and anxiety as well but I’ve never isolated so much that I cut everyone off to just live in a miserable little hole all by myself. I fight to feel better. I’ve never been to the point where I’ve given up completely on being a functioning person, so I want to know how it feels and what you think as you isolate to this degree.