I'm getting extremely worried - for the past 3 months, I've noticed cracks on both my ceilings and walls on my main floor. They started with cracks along my bedroom ceiling that follows the joist lines in my attic. Didn't think nothing at first, but then they started popping up in all 4 bedrooms. Last week, they started on the main floor and then cracks showed up in the walls and above windows. The house is 42 years old and was concerned with settlement issues as these were consistent with what I found online. Upon looking everywhere in my house, I also noticed that my main hallway now has a 1/4 inch gap from between my ceramic tiles and the baseboard. I had 4 foundation experts come to the house and because they didn't see any cracks in my outside foundation or in my bricks, they don't think I have any foundation/structural issues. Is it possible that my main floor is giving way and then everything above it is shifting? I am writing this at 4:30 in the morning and it's been like this for the past two weeks...I can't sleep and it's started to really affect my daily life....Has anyone encountered anything like this? Any help or suggestions would be appreciated.