You should try to obtain a loan modification, although the truth is that lenders are not cooperating on a large scale. But you should try.
The truth may be that you are stuck. The key is to prove hardship. Usually hardship means a death, divorce, medical bills, etc. It you are doing okay, just disappointed that you property value has dropped, then let me ask you this- if the reverse happened, and your homes value INCREASES by the same amount it decreased, would you be trying to give the extra money to the lender?
The investor that bought your mortgage - $585K. Can you imagine being that investor, and having the lender call and say "hey, they want to cut their mortage - you'll need to accept at $200K loss" - what would you do?
I am sorry if this is not helpful, but I think there are some good questions for you to consider.