Problem with Google Drive
Google Drive is a Online storage, not storing on your Mac.
Just like iCloud, one-drive and others.
What you have installed on you Mac is just the Google Drive app to manage online drive, not to store information on your Mac.
Go to your Google drive online (Log in) to see it directly. It will also show you how much storage you use and how much you have left.
Know that Google Drive also serves as storage for your Gmail.
If need be download and install the Google Drive app again.
I have 2 Google drives (one comes with each Gmail). I do not use the Google Drive app on my Mac (find it not nesessary). I go online log in to Google and can see and manage my drives there.