I am 2 years into chapter 13, and I am being layed off? How will that affect my bankrputcy?

I will receive a severance package, but I need to live on that until I get another job. I would like to take a portion and pay offthe 25% plan that I currently have, but I am being told that anything less than 36 months will require 100% repayment. After 36 months, it will still be more than 25%. I wouldn't necessarily mind paying off 100%j since it is my debt, but I won't have that AND enough to live on. Do the terms of a bankruptcy change if you lose your income? Can it be converted to a Chapter 7? Can you get payments deferred until you get a new job? Thanks!