Need some advice on my house.

I agree with a structural engineer.
Having retired from the civil engineering field ( private and public sector) as a technician I believe it would be the best option.
They will be able to determine what should be done to solve your problem.
Calculating using the size of structure, soil type and terrain ( it looks from your photo that you have a slope the posts are on). Also being in Minnesota the winters we can have can determine depth and size of footings. They may also give you some names of general contractors who have done this type of work.

Good luck and keep us updated.