Depends who signed for the house, if you both did, you both are owners, especially if you used both of your incomes as a basis for the loan.
You can sell back your half, she can sell hers, or you both can decide to sell out. You'll have to work that out if you haven't the means to support it yourself. You may look out on the web for mortgage calculators to figure out how much you can afford to spend with your income alone.

