Are you sure that your wife isn't possessed? Maybe you should call an exorcist or something.
I think somewhere along the line you have to figure out what it is you intend to be doing. This being her snuggly friend one minute and punching bag the next is ridiculous. And you take it on the chin like a trooper. You don't have to have her rant and rave at you one minute and then gloss it over the next. Would you do this if she was only a friend? Or only a short-term girlfriend? You can stand up for yourself. You can say, "I'm not going to have this anymore. If I'm so pathetic then just stay away. Stay out of the house. Stay out of my bed. I don't need this." She'll have more respect for you if you show that you don't intend to take it. You deserve better than her scraps of affection. You can tell her that her behavior is confusing and perhaps it's best if she simply back off. Besides, she has OM, what the heck is she doing snuggling in your bed? It's like a game of "who likes me more" to her. I'd refuse to play.
You cannot be lonely if you like the person you're alone with. Dr. Wayne Dyer