lost partition

I've have a 3tb fusion drive on imac that I had partitioned as a 2.45tb drive and a ~500gb other partition, when I was formatting the larger one the computer froze and I had to force shut down. That 2.45 drive is now not showing up at all. I've tried fresh installs, ran recovery mode and tried...

Installed windows with bootcamp a few years back. Suddenly started having issues windows so I attempted to remove it with bootcamp and ended up with a ghost partition. I tried various things to get space back but really just made everything worse. Got to the point where I was ready for a clean...