Speaking as a nationally know credit score and lending expert (book, rado shows, newspaper columns, etc.):
Did you get your credit scores from an on-line service or a mortgage lender. The scores are very different, higher or lower!
That is too low of a score for a 100% loan, period. Sub-prime lenders now require 580 or 600 or 620 for 100% financing, depending on lender.
Fannie Mae's "Flex 100" program may approve you on their computer underwriting now especially if you have a retirement account or cash reserves or stock/bonds saved.
Your self-employment is also a HUGE mortgage lending issue. Almost every lending company requires 2 years in business with various forms of proof of that being acceptable.
FHA lending is a small possibility. I have not been involved in that for years. They were recently in the news as possibly offering 100% financing but had always been 97%. FHA does not underwrite loans on scores. One year perfect credit and one year paying your rent (WITH PROOF--not money orders or cash or a letter from the landlord) are what makes FHA fly. 12 months on-time rent would be cancelled checks or a letter from a professional property managment company--or it showing on 12 bank statements in a row.
Mortgage lending is about 250X more complex than people think--it is NOT only about scores.