Getting a notice of default or a notice of sale in the mail is one of the most unsettling moments in the foreclosure process, but it helps to understand what these notices actually are before assuming the worst. A notice of default is generally an early formal step a lender takes after payments have been missed for a period of time, letting you know the loan is being treated as being in default. A notice of sale, when it comes, generally means a sale date has been scheduled, though the exact meaning and timing depend on your lender and the state you live in.
Neither notice automatically means the process is finished or that nothing can be done. In many cases, there is still time between a notice and any final sale, and what that time looks like depends entirely on your specific circumstances.

Rather than trying to guess what a notice means based on something you read online or heard from a friend, it helps to get a clear picture of what it actually means for your situation, specifically, and what your realistic options and timeline actually look like from here. You have been through a lot to get to this point, and you do not have to figure out the rest of it on your own.