You're welcome to throw in the towel and stop paying any time you want. You'll just suffer the consequences of doing so.
It sounds like you're concerned about losing your job "in the next few years." What are you doing to stem this off? Are you building up a side income? Are you building up portable skills -- ones that can be used anywhere? If you think you have a few years left, use them. Build something up. You may be able to recover more quickly, or last longer until you find a new job.
Some of my blogging friends have been at it about as long as I have, and they're in high-five, low-six figures now. For blogging. Some did it even faster. All it takes is time. Your expenses for starting a blog are $10/month plus cutting out two hours of TV / drinking / anything else consumer-ish to learn more about your favorite interest, write about it, and interact with the online community.
That's just one idea. Season to taste or choose a different meal altogether.
Are you frugal? Are you looking for ways to cut expenses? If you can find extra money to save a little bit more and knock out just one of those debts (say, the car), you'll be able to throw that payment at the student loan. Then they'll both be gone, and you can save up a cushion for yourself faster.
I just think it's a little weak to give up when you're not really in trouble yet. You're tight, but you can get through that.