How do I stop google photos from deleting apple photos?

I do not use Google Photos. But somehow I subscribed years ago and forgot it existed. Now I want to delete the Google Photos App and all the photos in it. But when I started this process, TO MY HORROR, it simultaneously *and automatically!* deleted the same photos from my Apple Photos App! I double checked the Google Photos app and I DO NOT HAVE the SYNCH’ing feature on. I think that even tho i turned it off, all the photos existing BEFORE turning the synch off remain synched. THIS IS A NIGHTMARE. PLEASE HELP!