Hi Diane,
You might consider using an auto-number column in your source sheet. This can generate a unique ID per row for you, which you can display in conjunction with the other data (including the column title) in your metric widget.
If someone needs to reference data back on the source sheet, they can search for that unique ID.
More information on using auto-number columns can be found in the help center: https://help.smartsheet.com/articles/1108408-auto-numbering-rows