You have a pretty good idea when the trustee's sale is going to happen. You can slow it down in a Chapter 7 Bankruptcy by a month or two; you can stop it permanently in a Chapter 13 by staying current and curing the default on the mortgage, assuming that you and your Chapter 13 Plan meet the standards for confirmation.
If you strongly want to stay in the house after the trustee's sale in Arizona, and you can't cure your default, and you don't want to file a bankruptcy, consider calling the mortgage holder and finding out if you can rent the place after it goes to the lender at the trustee's sale. Get it in writing, right?
I do strongly suggest that you talk to an experienced, AV rated, AVVO 10 bankruptcy attorney as soon as you know the the trustee's sale is in motion (you'll know; they post it on your door and in your front yard, as a general rule).
The reason I want you to talk to a board-certified, AV rated, AVVO 10 bankruptcy lawyer as soon as the trustee's sale starts is that the payments on the house count against the Means Test Calculation.
Putting it a different way, you may qualify for a Chapter 7 Bankruptcy PRIOR to the trustee's sale, and NOT QUALIFY after the trustee's sale.
That's kind of a big deal, you know?