SP Servicing Foreclosure

Since 2012, a mortgage company called Select Portfolio Servicing has held the mortgage (MTG) on our house.

The MTG is at 10%. Our house is worth less than half of what we owe. It's falling apart, and it's time to leave. We contacted SPServicing about a Deed In Liu. They denied that and stated that it would be a foreclosure.

What can I expect as this progresses? How long does something like this take? I'm not afraid to admit that this terrifies me.