Major problems with main exterior wall of house.?

Bought house in 2008. Inspector ped everything. Recent owner supposedly fixed roof but left hole by old fireplace which leaked in house the last 2 yrs. We noticed a couple months ago our floor in kitchen and bath were rising up and tiles were coming up and walls were crumbling in on one side. So we started gutting everything. We have found that this was a brick house at one time, they plastered over it. The bricks from old fireplace are all falling down and it's all cracked up to the roof and leaning like its going to crash in. We found there is a steel cable with each end hooked to chains hooked to each side in attick like it's holding the walls from North to south together. The floors are wet and ruined in bath and kitchen. The joists are bad in basement. We don't think all this can be fixed easily. Our frineds think we should get a lawyer, but everyone I've called said it's been since Oct 2008 since we've bought the house and don't think anything can be done to anyone. Inspector said he couldn't inspect attick because it's 0% unaccessible. Does anyone know if there is anything we can do about this? They might have to condemn the house I think. We just got screwed cause we thought this house was sound. We went through USDA-Rd for our loan. Our friends say with us going through the gov. for a loan, you'd think they would have made sure the house was inspected GOOD, or we wouldn't been able to get a loan for this house. Can anyone help us with suggestions?Oh and our kitchen and bath and two back porches were added to the end of this house before we bought it, so that whole support wall is whats bad between the old part and new part of house. Thank You.