It’s been a long time since it’s happened to me, but I learned to wait and patient and it seemed to clear up after awhile. Doesn’t seem to be the case for you though after several hours.
If I recall, if a column went missing and you got the message, clicking the remove button would pretty much delete any components that use that column. Seems like Glide handles things a little more gracefully now and doesn’t delete anything, but may require you to reconfigure anything that used that column.
You may want to create a duplicate of your app. First to have a hopefully functional backup if things go bad with the original, and second, just to see if the issue clears up in the duplicate.
It’s weird, but when this happens, it seems like Glide gets stuck and refuses to even check the sheet again to see if the data is restored. I don’t know why. My theory to get it working again is that triggering a data change from the google sheet may overcome that and get things syncing again, but it’s hard to say if that’s the case. Wish I had a definite answer for you.