Google drive is terrible software for backing up your files. I'm now trying to get rid of it but am having a hard time getting back all the gigs that it devoured. I read the recomendations for doing so here:
I was backing up 20 gigs worth of dating on my mac with google drive. I moved those files to external hard drive, deleted google drive but till now I have not got back any of the gigs that it devoured. In fact, I have not freed up any space on my laptop since I deleted google drive. I cannot access any of the docs that was contained in those 20 gigs but I have just as much free space on my laptop as before.
I should also add that there are a lot of companies out there claiming to clean up your mac. I'm not using any of them since I believe them to be malware.