If you have signed a contract there has to be a section regarding loan or your loan contingency. Since your spouse is laid off you are no longer qualified buyers and thus can not get a loan. This should be a good enough reason to void the contract. If they give you a hard time you should contact an attorney. Sorry about your spouse lost of job. Hang in there things will get better.
Prudential California Realty
Find another buyer to take over your contract is no guarantee of safe back out.