I'm sure you don't add to her stress, nor, most likely, is there anything you can do to lessen it. OK, of course, if you WERE a uncaring, lazy H, you of course could add to her stress, but then most likely you wouldn't be here, either.
Point is, it is her who has to deal with these issues, you just have to draw strong boundaries. I agree with whoever said remove yourself and the kids from the house when she gets that way. If you can, I like JJ's suggestion too. Is there someway you could have a video camera ready, so when she blows you could get it on tape? It may be that showing it to her is enough to get her to realize what she is doing?
I would suggest you do what I'm doing. Get an exit strategy. Maybe if she realizes you're serious? Who knows. I wouldn't advocate this for everyone, but there is a lot of evidence to suggest people like this - who go out of control - don't get it, have no motivation to stop, until their whole support system is taken out from under them. You are 'enabling' her, just by letting her do that and coming back (or staying) each time. Telling her you don't love her, or that you've had enough isn't enough. You're still there - she still has you to 'hold onto'.
Thing is, you have to mean it. You have to willing, and able, to leave. It really may take that.
Ok, your sitch is different from mine, but not by far. You've followed my story, you know I've done just about everything but stand on my head to get H to listen, instead, I get the same kind of angry outbursts I've been getting for 16 yrs. He won't go to counseling, won't talk with me, won't take responsibility for his part of the R (not to mention the housework...)
So what do I do? Learn what I can to keep myself safe, next step is to try, once again to get H to a counselor (we're talking psychiatrist this time). If that doesn't work? I might just drop that I visited a lawyer today...show him the filled out D application(no, I haven't done it yet)...
Yes, I hope - pray - he 'calls my bluff' along the way, I hope any one of these steps is enough to wake him out of whatever fog he's living in. If not?
Like you, Barney, the very last thing I want to do is D. I DON'T want to leave my home, I don't want to break up my family. But I also don't want my kids to grow up believing their father's behavior is acceptable. As NOPkin said to me once - taking no action is a decision as well. Your kids are watching. They do realize what's going on. And they are learning from whatever you do - or don't.