It sounds like you are at a cross roads where you are damned if you do or damned if you don't. You could stay and suck it up, you could go, or you could face this. All are hard work. which path would lead you to your joy and be better for everyone.
I think if I were you I would encourage her to a path that is better for both of you at this point and start learning and educating yourself about what kind of poly would work for you. What do you have to lose?
There are lots of posts to read here that could help in answering her and your questions so that both of you know what is possible and what isn't. Doing a tag search will show you a tag cloud that will bring you to some really good stuff. I suggest reading "lessons" and "foundations" first.
There is a link that I love about finding joy through becoming vulnerable that is by Brene brown. Maybe it will inspire. http://www.ted.com/talks/brene_brown...erability.html
hope it helps. I have written about it in my blog also. pg 50 post 491. good luck