Your soil has shifted and caused the slab to fail, or you have a water leak and eroded the soils and caused a cave in.
Either way, you do need to contact your insurance company and they will send out a plumber to view your plumbing.
I had this same thing happen last year. They will open up your comode and send down a camera on a line, then the monitor will show the path of the camera and you will be able to see the problem.
If the slab has cracked, then surely plumbing lines have broken or becoming under undue stress.
You will problably need some jacks installed to bring up the slab to normal position. Usually you need one jack per 8 foot. Then the area is backfilled and filled with a oil well chemical that when wet will inflate and assist in holding up the slab.
Get ready for a nightmare if you have a beautiful landscaped lawn.
Our pipes, cast iron, gave way after 30 years and we had our slab foundation pipes re routed via large tunnels under the slab. so, no inside work was done at all.
Don't do anything without the insurance company first documenting everything.