In theory you should never have left the house. If there is no legal separation in place and you are not violent you can do what you like.
However. it is obvious that would not help the situation. I think the best route at the moment is to see your lender. They may be happy to reduce the payment to one you can afford pending sale. BTW, dont assume it will be 50/50. The court will look at your overall financial arrangements during the marriage, and may award you you more since your wife is the higher earner.