As a brief follow up to Chet's excellent remarks. I agree; try to stay afloat as long as you reasonably can and contact an attorney ASAP. An experienced attorney will know who to contact (e.g real estate liquidation department; for those that cannot modify) and will be able to provide the necessary guidance and hand holding that you will need. The fee you will pay him or her will be much less than paying 90k. One thing to keep in mind. Some banks will not entertain a DIL until you have at least gone through the short sale route first. For example, Wells Fargo requires that the house be on the market for 90 days before they will consider a DIL.
Final thought and just speculation. Given that you are in Nevada and the bank can obtain a deficiency judgment, I am not sure what incentive they will have to accept a DIL. Maybe they would if you work with them first and go through the hoops the may want. My guess, if you just stop paying and do not try to work something out (without litigation) they would just foreclose and obtain the judgment.
For finding an attorney, also check the local bar association and also the Neveda State Bar website which may allow you to find the appropriate attorney in your local area.
www.nvbar.org Each bar usually has a free lawyer referral service that will connect you with an atrorney that can help. Also, if you go through the service, the initial fee for the consultation will be free or drastically reduced. I think Nevada is no more than $45 for the initial consultation when you find an attorney through the service; verify this before yo meet face to face. Check it out and Good luck!