Who pays?

[lisa4]

I bought a home with my roomate. It is now a nightmare. What I thought would be a good investment vs. throwing money out the window for rent, has now turned into a huge headache. She moved out in September of last year and I moved out in December and we placed the house on the market. I paid the mortage for the months I was in the house as I would need to for rent anyway. The house sold and then the buyers financing fell through. Now, neither one of us live in the house, yet we still have financial obligations to the house. I have been paying all the bills - she says she can not afford to pay two places so she is not going to. Both of our names are on the mortgage. Wondering what my next step should be.