Hi Daniel, I'm just sitting here watching the Blues Brothers movie and they had the scene with the El train shaking the hotel they were in.
Is this a ground floor? Is there a basement or crawlspace underneath? These 7 bags of cement, did you put them under the floor or on top? What size floor joists do you have? How thick and how many layers is the subfloor and floor? Is it just a problem in the kitchen area or is the floor in the whole house out of level? Need more info to figure out what you got.