I defaulted on my private student loans. Currently

I defaulted on my private student loans. Currently, I am working with the collection agency Allied Interstate. I've been making payments on time for a little over a year now, so I am in good standing with them. The payments are extremely high $425 a month. And I owe $40K in private student loans. I just got laid off from my job yesterday and applied for unemployment. There is NO way I can afford these payments now. I could barely afford them while I was working. I am curious to know what my options are. I am assuming I will only have enough money from unemployment to pay living expenses - rent, utilities etc. On Monday, I need to contact Allied Interstate and tell them about my situation, but I would like to do some research first so I know what my options are. I am extremely worried that I will be sued because I can't pay. Thank you for your time and I appreciate any advice you can give.