I think you may find that the D drive was not to store your back ups (too small anyway) but it is your recovery partition if the OS fails and you need to restore C to factory settings.
It looks as if you have wiped off your safety net.
Best phone camera 2017
Stunning new film posters by Hattie Stewart, Joe Cruz & more
iPad Pro 10.5in (2017) review
28 astuces pour profiter au mieux de votre iPhone