@Merlin - welcome.. and that sucks!
you can raise a help ticket at this link and they will get on the case shortly.
Have there been any changes made to the Google Sheet tab(s) that receive data from the typeform? That will likely cause this issue to happen. I have seen several posts here in the community talk about this happening from time to time, and that seems to be the culprit.
If you do remove the integration and re-create it, you might have to create a new spreadsheet as opposed to linking to an existing one. If the existing spreadsheet is in someone else’s account that might also cause an issue. One limitation i have seen posted is that IF you recreate your sheet and then say ‘yes’ to adding existing records to the sheet, it will max out at about 3,000 rows of data - i am not sure why but someone from the Typeform support team should be able to provide the details.
good luck
des