I had this exact issue just now. I researched and compiled all of the answers. Surprisingly it worked.
1) On my PC desktop, I right clicked and created a new folder. I named it "Empty folder".
2) I plugged in my phone to computer, opened iTunes.
3) Clicked on my phone on the left
4) Clicked on "photos" on the top
5) Clicked the box "Sync Photos with"
6) Choose the dropdown and "choose folder"
7) Click "desktop" option
8) Click on the folder that you created and named whatever you named it.
9) Click "apply/sync"
In doing so, it deleted the "Photo Library" with the little sunflower as well as a "My Photos" album it had also created, but it left all of my other photos that I wanted to keep.
I'm shocked that this actually worked.
Hope this helps you.