Wow this is hard. I apologize but this is going to be a long post. . . .
My wife and best friend of 11 years dropped the 'we have to talk' bomb on me just a few days ago - on my birthday no less

Cool as can be she said it was all over, that she still wanted to be friends but she was moving to the guest bedroom until it was feasible for us to find separate residences - we own a house together but I'm in my 3rd year of physician assistant school and completely poor, she doesn't make much money so who knows when that will be, certainly not for 5 or 6 months.
The backstory is that we were totally in love for the first few years then I guess we just settled in to a routine of work and chores (no kids for better or for worse). We were both very comfortable and secure but the passion definitely waned due to mutual neglect. Somewhere in there I became pretty dissatisfied with my job and decided to go back to school. At the same time she decided to quite her job and start her own business. We talked about this together and decided that both would be good way for us to be happier individuals and therefore eventually a happier couple.
In retrospect this was obviously not a brilliant plan, it did nothing to bring us together and we were both working like dogs. Our relationship was totally neglected an became essentially sexless (no thanks to either of us). About two years ago my wife travelled home alone to visit family and friends, I haven't really had time to travel anywhere because of school. While she was there she met some guy she went to college with 15 years ago. They started emailing each other and unbeknownst to me got very involved over the internet. For a good long time it was just email then last summer she went home again and then drove 5 hours to go visit him.
When she came home she was all energetic and practically glowing. At the time I thought 'great, here's the girl I fell in love with a decade ago, awesome!' Little did I know what was really going on. A few weeks later she started planning a road trip for the fall. She asked me if I wanted to go, know that my schedule wouldn't allow it. She said no big deal, she'd find a friend to go with her. Couple weeks later she tells me she's going to go with her male friend and did I have a problem with that? I asked should I have a problem, she said no and I said I trust you honey, I just want you to enjoy life while I'm stuck in school (I know, I'm and idiot). I'm sure you all know how this ends so to make a long story short she gets back from her week long trip and can't look me in the eye.
After three days of avoiding me some little thing triggered a fight and she blurted out the whole thing. She was sorry about the lies but not much else. I got an earful of how Mr. Wonderful gave her butterflies and had reawakened her sexually and a whole lotta other stuff I won't go into.
It was a long night of talking, I told her I still loved as much as ever and I didn't want us to split. We both took ample blame for all the boredom and neglect our relationship had suffered over the previous years. She agreed we should work on it and I said that she would have to break off the affair in order to give us one more chance. But of course she didn't break it off, he kept calling and emailing, and she would come home in a foul mood one day, a crazy sex maniac the next. All the time I was on my best behavior trying my best to be as loving and attentive as I know how knowing what I had to lose. We had a few more heart to hearts over the next couple of months where she divulged her difficulty in severing the affair and her mood swings were due to the sexual tension with her boyfriend. I thought I had won her back just before Christmas - the guy had come to our city to whisk her away back East for the holidays - she said no and sent him packing. But of course this wasn't the end of the story either.
We did have a wonderful Christmas and New Years, as happy as we have been in years. We promised to start couples therapy in a month and to talk more. Then she decided that she would try a few sessions of individual therapy as well before we went together. The difference was night and day. The morning before her 1st session I don't think we could have been more in love, when she got home that night she looked at me with hate for the first time in our relationship. For the next three weeks there was no affection, she was just rude and mean. Then on my birthday she seemed to soften up, we went out for some dinner and some fun and had a great time, until we got home and she laid the mushroom cloud on me.
So here I am trying to figure out what the hell I can do. I haven't eaten a thing in 5 days, I was sent home from my last rotation for basically having a nervous breakdown in front of the head of pediatrics, I spent 2 days in bed listening to Death Cab for Cutie, I'm a wreck. I am still in love with her, I can't imagine my life without her. She says she still loves me but I don't make her heart flutter anymore, she wants us to be best friends but is too angry with me for depriving her of those feelings of falling in love she had with her boyfriend and for keeping her from experiencing life to the fullest to stay in the marriage. She seems to have this twisted idea this whole thing wasn't going to upset me, that we could live happily together as roommates as though life wouldn't change when she made this decision. I'd stay at home, my old boring self, while she went out and had affairs and travelled the world.
I guess this is more of a rant than a plea for advice but do I push her away to protect myself, do I beg and plead, do I just wait and hope she comes back to me? Now she doesn't want marriage counseling, her therapist is telling her she should move on with her life and yet she is still in the house and there's no way for either of us to get out. She's sorry she hurt me but says there's no chance for reconciliation anymore. How do I pull myself out of this pile of crap?