Outonalimb.
Step back a little bit and review.
I assume you TODAY can not afford the house.
If your circumstances are such that surrendering is your best option ,then go for it.
But do not just hand back the keys.
Contact lender ,make the appointment and show lender your situation.Let Lender lead you through the process , at all times keep copies of all documentation and do not be bullied or put your signature to anything until you are sure it is in your best long term option.
With Banks I would always be afraid that they take the quick option but the (hit) might come to you in future life.
That said, be fair with them.
And good luck.