Hi Water, How are you doing? Happy Belated Birthday.
This post is a heart-wrenching. Is there a way that you can kindly say when he is ranting like this that you are not willing to partake in a convo. of that nature/or while he is upset/or when he has this tone/etc. and to tell him to call you when he can speak rationally? Obviously, going down all these roads is only going to create negative consequences.
I don't know what he has conjured up about you or why. It sounds like he has been trying to set you up for failure. But, I know, that us giving you our opinion on him doesn't do much for YOU. I'm just concerned about you listening to stuff like that which is abusive and meant to hurt. You don't need to take it, gf.
You know you are a lovely, honest, committed person. If he can't see that right now, it's not really your prob. anymore. I don't know how you can help him-other than what you do-be there for him and validate his feelings. Did he ever get on med's? Please take care of yourself and don't let yourself get sucked in. I know it is easier said than done, but do it for you.