Apply for modification

I've had my mortgage since June 2005 and have never been late until this month. Over the past three years, my husband became sick and died, my daughters business was badly damaged and I needed to support her, many legal fees, and I drained my savings and retirement accounts. I just ran out of money from a lawsuit settlement and was faced with not being able to pay the October mortgage. I don't care about my credit anymore and am looking at the HAMP modification. The loan is with BofA. Do I start sending them the paperwork to apply for the modification right away? What happens during the time they are considering the application? Do I need to pay them? I'm 70, when do I have to worry they will throw me out of the house? Thanks for any advice!