Try some other folks and see what the GENERAL concensus is.Dont put your eggs in one basket.
Why is it sinking in the first place?
Did someone set up a transit for hieghts and plumb the exterior of the house?
Are ther cracks in the foundation and how big?
Unfortunatly if the experts all are in agreement, there are not to many more options that are not the expensive type.
How much property do you have? Can the house be moved to another spot for the same amount of money?Probably not.
My family is from Iowa...I dont remember any hills!!!
Remember the leaning tower of Pisa?.... Charge admission!!