I am also really stuggling with the anger and resentment. I had some great advice on my thread so I thought I'd paste it here and maybe it will help you too.
I dont think it's all that diff from what other WAS deal with. They get to a point where they aren't happy.. they want to be happy.. it's not really us necessarily.. it's just that life has changed or they have problems and they can't find their way back into the marriage. At least that's the way it is with my XH. His depression; the way he handles problems; his childhood; baggage we've built up in our R. He loves his family, or at least wants to, but he's not mentally or emotionally able to pull it off right now. Maybe that's what answered the Whys for me. I saw that it doesn't HAVE to be about him not caring or wanting to hurt his family. The only answer that makes sense at all, is that he just can't and even he doesn't know why.
I'm not sure uf that helps you but perhaps if you look at your wife as being someone who is unhappy and doesn't know why. So, she blames you and lashes out at you. It isn't right, of course, but she just isn't strong enough right now to handle the emotions. Stay firm and hold up your boundaries but also be compassionate and compromise where you can.
WCB
God grant me the serenity,
to accept the things I cannot change,
To change the things I can,
And the wisdom to know the difference.
- Reinhold Niebuhr