I suggest you contact Home Loans For All. They deal with all types of situations including this one. They have shown us they're experts even with USDA home loans. I'll include a link to their website. Hope this helps.
You can get approved with under a 600 credit score for home loan not sure about USDA though. I have a 580 credit score and got approved for FHA just 3.5% down, The Lenders Network sent me to one of their lenders to get me approved so I would try there.