Sorry to say, this is the worst time for someone with less than good credit to try to obtain a home loan. Due to the increasing numbers of homes going into foreclosure, banks and lending agencies have tightened the requirements and what you need in order for you to qualify for a home loan.
You may have to work on bringing up your credit score and save money so that you will have a larger down payment available when your credit score has improved. Not much you can do when the mortgage lenders are reeling from the high numbers or home owners defaulting on their loans.
I wish I had better news for you. Maybe someone else will have some ideas, but doubtful you will be able to find a lender willing to take a chance on you at this time.