hmmmmm... this sounds somewhat like me, a long time ago.

When you said, "We were proactive, worked as a couple to understand his moods and triggers. Then, about a month ago, he became angry with me, started to shut me out, became evasive and passive aggressive" It brought to mind the times that similar things had happened to/with me.

I can explain myself and my thinking that I had then, not now, and maybe that will help you in your journey?

Yeah, at first everything would be new and exciting. The sky would be the limit. I would drop all inhibition and open up at first. Be as open as possible and try to work on the things that were brought up. For me, this would be the problem. That is because after so long of working on myself, focusing on my moods and triggers, everything like that, I would get tired. I would start to think, "Why do I need to do all of this? If I'm not good enough the way that I am, then screw it." I would build a resentment, just like you said, but that is because of this kind of thinking. I know for me I can only take so much of focusing on my moods and triggers before I feel resentful of the other person. That is why I manage my illness alone, only sharing with my wife the good parts, or the serious ones.

It just all gets tiring, it gets to be too much. The problem is the beginning. the start of the relationship in my opinion. It sounds like it was intense. brought out intense desire to be with each other. he probably worked so hard to make it right this time around, that he got too far ahead of himself. He couldn't keep it up and became resentful over that fact. And once resentful, one has to justify it by any means. And that's where you get the passive aggressiveness. Breaking up because he felt like he couldn't do it. he must have felt like a failure... and eventually like you didn't deserve him. depressed thinking.

If you care to analyze it enough, it's kind of like quitting smoking lol.
Start off great
work through the first part of it okay
but it wears thin, wears you out
then you have just one, justifying it the whole time
and it makes the rest harder
and it gets too tiring
and soon you have another, and another
and you feel guilt and failure and even pain cuz of it
and before you know it, your smoking more than before

It's the pattern that makes it like quitting smoking in my opinion.
The pattern of wanting something so bad...
and doing great at it, with enough effort at first...
but realistically, effort alone is never enough....

sounds to me like he wasn't stable to begin with. but, he needed to be to be with you. he wasn't honest about where he was in life with his illness... he just needed to make it ok for the sake of the relationship. when he couldn't do that anymore, he felt like he failed. and the resentment and the guilt and self hate must have kicked in and the coping mechanisms for that is to justify everything so that it makes sense...

in this manner, a person with this illness can hurt themselves beyond any recognition before they come to and realize what has been done. It is very sad.

Okay, I'm done rambling....

going out on a boat with two friends today!

hope that I helped in some way or another...